NDT HANDBOOK

Non-Destructive Testing
Inspector's
'v
Handbook
Visual Inspection (VT)
Liquid Penetrant Inspection (PT)
Magnetic Particle Testing (MT)
Ultrasonic Testing (UT)
Eddy Current Testing (ET)
Radiographic Inspection (RT)

Preface
This reference book was designed for use in the field and to support onthe-job training. It should not be
L ised as a standard or referred to as a stand-alone document. This book covers basic formulas, charts, and other
NDT related information.
Dedication
To all the people who have influenced my naval career and where I am today in the NonDestructive field.
Thank you. I originally started this project as a self-knowledge application and began receiving comments from my
fellow colleagues requesting
a copy. I soon realized that this would prove to be an invaluable tool for general infomation in our field. I have received support from both military and civilian personnel and have taken a sample
of their suggestions and compiled them for you, the end user. I wanted to take personal credit for this project and
realized it would not benefit the NDT field as a whole. Instead, I encourage you, the end user, to change,
manipulate, or configure this
book for yourself. In closing, "Share the Wealth with Others."
Last Revision Date
20 April 2002
Contact Information
[email protected]
ndthandbook.zapto.org
Disclaimer
This book is not intended for sale or any monetary benefit to the editor.
Inspector's Handbook

Table of Contents
Scope of Standards .............................................................................................................................................. iv
.
.
................................................................. Chapter 1 - General Information
Id
.............................................................................................................. Schedule Designations of Pipe Sizes
. Copper Tubing Wall Thickness ..................................................................................................................... 1 1
.......................................................................................................................................... . Decimal to Inches 1 1
. ............................................................................................................................ Temperature Conversions -1 1
Fraction to Decimal Equivalent .................................................................................................................. 1-2
Decimal to Second Conversion ..................................................................................................................... 1-2
...................................................................................................................... Numerical Place Value Chart 1-2
Elements of a Nondestructive Examination Symbol .................................................................................... 1-3
Elements of a Welding SyrnboL .................................................................................................................... 1-3
.................................................................................................................................... Examples of Grooves 1-4
.................................................................................................................................. Basic Joints (Welding) 1-4
................................................................................................. Order of Performing Arithmetic Operations 1-5
.................................................................................................................................... Ratio And Proportion 1-6
.................................................................................................................................... Calculation of Area 1-7
Weld Area Calculation .................................................................................................................................. 1-7
....................................................................................................................... Common Symbols and Terms 1-7
............................................................................................................... Solution of Right-angled Triangles 1-9
................................................................................................................... . Basic Illustration of a Weld 1 10
....................................................................................................................................... Welding Processes -1 1
.................................................................................................. . Backing Ring Common Defect Locations 1 12
.......................................................................................... . Consumable Insert Common Defect Locations 1 12
............................................................................................................ Primary Processing Discontinuities 4
Finish Processing Discontinuities ................................................................................................................
.............................................................................................................................. Dial Indicating Calipers 1 - 15
............................................................................................................................................... Micrometer 1 - 15
................................................................................................................. Thread Terminology (fasteners) 1 - 16
............................................................................................................................. Tap and Drill Size Chart: 1- 16
................................................................................................................. Julian Date Calendar (Perpetual) 1 - 17
.............................................................................................................. Julian Date Calendar pap Year) -1 -18
Chapter 2 . Visual Inspection ...................................................................... 2-1
........................................................................................................... Common Definitions and Examples 2-1
Chapter 3 . Liquid Penetrant Testing .......................................................... 3-1
Common Terms and Definitions .................................................................................................................. -3-1
Prorated Maximum Number of Indications .................................................................................................. 3-6
Areas of Circles ............................................................................................................................................. 3-6
Penetrant Wetting Characteristics ................................................................................................................. 3-7
Chapter 4 . Magnetic Particle Testing ......................................................... 4-1
............................................................................................................. Common Definitions and Examples 4. 1
.................................................................................................. Longitudinal Magnetization Math Formula 4F7
.................................................................................................. Prorated Maximum Number of Indications -
............................................................................................................................................. Areas of Circles 4
Common Types of Magnetization ................................................................................................................ 4-9
Inspector's Hmmk

.......................................................................................................................... Theory: "RigheHand Rule -4-9
........................................................................................................................................ Hysteresis=Curve -4- 10
.............................................................................................. Magnetic Particle Field Indicator (Pie Gage) 4- 11
. ....................................................................
*& Chapter 5 Ultrasonic Testing
5- 1
................................................................................................................... Common Terms and Definitions 5-1
............................................................................................................................ Common Math Formulas 5- 12
............................................................................................................. Calibration Chart . UT Shearwave 5- 13
FPADSCRhD .............................................................................................................................................. 5- 14
............................................................................................................................................. Velocity Chart 5- 15
Chapter 6 . Eddy Current Testing ............................................................... 6-1
................................................................................................................... Common Terms and Definitions -1
Two Types of Electrical Current ................................................................................................................... 6-6
Conductivity and the IACS ........................................................................................................................... 6-7
Right Hand Rule ............................................................................................................................................ 6-7
Magnetic Domains ........................................................................................................................................ 6-9
Depth of Penetration ................................................................................................................................... 6-12
Limitations of Eddy Current Testing ......................................................................................................... 6-18
Advantages of Eddy Current Testing ...................................................................................................... 6 18
Summary of Properties of Eddy Currents ................................................................................................... 6-18
Eddy Current Relationship of Properties ............................................................................................ 6- 18
........................................................... Chapter 7 . Radiographic Inspection 7-1
Common Definitions and Examples ............................................................................................................ -7-1
.......................................................................................................... Structure of the Atom and an Element 7-8
............................................................................................................................. Components of an Isotope 7-8
Characteristics of A Radioactive Element .................................................................................................... 7-8
Two Types of Radiation ................................................................................................................................ 7-8
History of Radiography ................................................................................................................................. 7-9
60' Coverage for Pipes and Location Marker Measurements .................................................................... 7-11
Common Math Formulas ....................................................................................................................... 7 12
Magic Circles ....................................................................................................................................... 715
Single Wall Exposure I Single Wall Viewing for Plate ........................................................................... 7-15
Single Wall Exposure 1 Single Wall Viewing for Pipe ............................................................................. 7-16
Double Wall Exposure 1 Double Wall View (superimposed) ................................................................... 7-16
Double Wall Exposure I Double Wall View (offset) ............................................................................. 7-17
Double Wall Exposure 1 Single Wall View ............................................................................................... 7-17
KILLER CARL ........................................................................................................................................... 7-18
Penetrameter Material and Group Numbers .............................................................................................. 7-18
Penny T-Hole Maximum Density ..................................................................................................... 7 19
2% Penetrameter Quality Conversion Chart (X-RAY ONLY) ................................................................... 7-20
Basic Components of an X-ray Tube .......................................................................................................... 7-25
Types of Scatter Radiation .......................................................................................................................... 7-25
. .
Radiographc Fllm Interpretation ................................................................................................................ 7-25
. .
................................................................................................................ Radiographic Film Interpretation 7-26
................................................... Probable Causes and Corrective Action for Automatic Film Processing 7-50
................................................ Probable Causes and Corrective Action for Processed Radiographic Film 7-51
Inspector's Handbook iii

Scope of Standards ..
NSTP 271 REQUIREMENTS FOR NONDESTRUCTIVE TESTING METHODS
- -
This document covers the requirements for conducting nondestructive tests (NDT) used in detenninin(
presence of surface and internal discontinuities in metals. It also contains the -mum requirements necessary .
qualifL nondestructive test and inspection personnel, procedures, and nondestructive equipment. This document
does not contain acceptance criteria for nondestructive test. This document does not cover all of the requirements
for performing nondestructive tests in an underwater environment. Nondestructive tests in an underwater
environment shall be performed as specified in NAVSEA S0600-AA-PRO-070.
NSTP 248 REQUIREMENTS FOR WELDING AND BRAZING PROCEDURE AND PERFORMANCE
QUALIFICATION
This document contains the requirements for the qualification of welding and brazing procedures, welders,
welding operators, brazers and brazing operators that must be met prior to any production fabrication. It includes
manual, semiautomatic, automatic and machine welding and brazing of ferrous, nonferrous, and dissimilar metals.
The qualification tests required by this document are devised to demonstrate the adequacy of
the welding or
brazing procedures and to demonstrate the ability of welders, brazers, welding operators and brazing operators to
produce sound welds or brazes.
NSTP 278 REQUIREMENTS FOR FABRICATION WELDING AND INSPECTION, AND CASTING
INSPECTION
AND REPAIR FOR MACHINERY, PIPING, AND PRESSURE VESSELS
This document contains the welding and allied processes (except brazing) and casting requirements
including inspection for the fabrication, alteration, or repair of any item or component of machinery, piping, and
pressure vessels in ships of the United States Navy.
MILSTD 2035 NONDESTRUCTIVE TESTING ACCEPTANCE CRITERIA
The acceptance criteria contained herein are for use in determining the acceptability of nondestructive t. -
(NDT) discontinuities in castings, welds, forgings, extrusions, cladding, and other products when specified by the
applicable Naval Sea Systems Command (NAVSEA) drawing, specification, contract, order, or directive.
NSTP 1688 FABRICATION, WELDING AND INSPECTION SUBMARINE APPLICATIONS
This document contains minimum requirements for fabrication and inspection of submarine and
non
combatant submersible structures, including shipbuilding practices, specifications for materials, weld joint design,
workmanship, welding, inspection, and record requirements.
MILSTD 1689 FABRICATION, WELDING, AND INSPECTION OF SHIPS STRUCTURE
This standard contains the minimum requiremeas for the fabrication and inspection of the hull and
associated structures of combatant surface ships. The requirements for shipbuilding, materials, welding, welding
design, mechanical fasteners, workmanship, inspection, forming, castings and records are included. It also applies
to those submarine structures which are not high-yield strength steels.
MILSTD 22D WELDED JOINT DESIGN
This standard covers welded joint designs for manual, semi- automatic, and automatic arc and gas welding
processes for use onmetals and weldments, as applicable, when invoked by a fabrication document. The welded
joint designs shown herein represent standard joint designs used in welded fabrication and are not intended to be
all inclusive.
Inspector's Handbook

NSTP CHAPTER 074 - VOLUME 1 WELDING AND ALLIED PROCESSES
This chapter furnishes both the minimum mandatory requirements (indicated by the word shall) and
guidance information (indicated by the words should or may) necessary for welding, brazing, inspection, and
safety when used for ship maintenance, repair, and alteration.
-NSTP CHAPTER 074 - VOLUME 2 NONDESTRUCTIVE TESTING OF METALS QUALIFICATION
AND CERTIFICATION REQUIREMENTS FOR NAVAL PERSONNEL (NON-NUCLEAR)
This chapter is Mshed to ensure achievement of uniform and reliable nondestructive tests on naval
materials and components, implementation of the training, qualification, and certification programs described
in
this chapter should be followed precisely.
Inspector's
Handbook

Decimal to Inches
inches 1 12 = decimal
decimal 12 = inches
Temperature Conversions
-
Fahrenheit = (915 * C) + 32
Celsius
=
(F - 32) * 519
Copper Tubing Wall Thickness
Inspector's Handbook

Fraction to Decimal Eauivalent 1 I Decimal to Second Conversion I
I PLACE) I
Numerical Place Value Chart
I
ForExample2,262.357.619844
2
THOUSANDS
bI UNITS I 1 I LI
2
3
5
MILLIONS
100,MK)
TEN
THOUSANDS
THOUSANDS
HUNDREDS
TENS
1,000,000
E
10,000
1,000
loo
10
D
1
C
1
A
6
HUNDREDTHS
9
8
4
TENTHS
I
1/10 I 0.1
1/100
THOUSANDTHS
TEN
THOUSANDTHS
HUNDRED TEN
THOUSANDTHS
MILLIONTHS
0.01
111,000
1110,000
1H00.000
111,000,000
0.001
0.0001
0.00001
0.000001

Elements of a Nondestructive Examination Symbol
Elements of a Welding Symbol
NUMBER OF EXAMINATIONS LENGTH OF SECTION TO BE
EXAMINED
REFERENCE
LINE
-EXAMINE IN FIELD
SPECIFICATION OR OTHER
REFERENCE
EXAMINE-ALL-AROUND
TAIL ARROW
GROOVE ANGLE: INCLUDED ANGLE OF
FINISH SYMBOL COUNTERSINK FOR PLUG WELDS
ROOT 0PENING:DEPTH OF FILLING FOR PLUG
GROOVE WELD SIZE AND SLOT WELDS
DEPTH OF BEVEL; SIZE OR STRENGTH FOR LENGTH OF WELD
CERTAIN WELDS PITCH OF WELDS
-FIELD WELD
SPECIFICATION OR OTHER
NOT USED)
REFERENCE (OMITTED WHEN T
WELD-ALL-AROUND
TAIL ARROW
NUMBER OF SPOT, SEAM, STUD,
PLUG. OR PROJECTION WELDS
A
RADIATION DIRECTION EXAMINE ALL AROUND
Plug or Spot or Back or Flange
Fillet Slot Stud Projetiin Seam Backing Surfacrng Edge 1 Corner
FIELD EXAMINATION
/
L
GROOVE
Basic Weld Symbols
Square
- - LL-
- - -
i
Inspector's Handbook
Scad
-- .
- 7r -
Weld all
around
V
-v-
- -A -
Field Weld
/--
i
Mvel
--
-1'T--
Melt
~hrough
-Tee
U
--Y--
- -A- -
Consumable
Insen
(Square)
J
--Y--
--K-
Backing
or Spacer
(Recrangle)
Flare-V
-I/_-
-2 x- -
,Contour
Flare-
bevel
--LC-
--rc-
Flush
or Flat Convex Concave

Examples of Grooves
square Single J Single Bevel
Single Vee Double Bevel Single U
Basic Joints (Welding)
I
I Lav
' /I corner / /
we Tee
Inspector's Handbook

Order of Performing Arithmetic Operations
When several numbers or quantities in a formula are connected by signs indicating that additions,
subtractions, multiplications, or divisions are to
be made, the multiplications and divisions should be carried out
1,
%st, in the order in which they appear, before the additions or subtractions are performed.
Examples: 10+26X7-2=10+182-2=190
18+6+15X3=3+45=48
12+14+2-4=12+7-4=15
When it is required that certain additions and subtractions should precede multiplication's and divisions, use
is made of parentheses 0 and brackets n.
These indicate that the calculation inside the parentheses or brackets should be carried out complete by itself
before the remaining calculations are commenced. If one bracket is placed inside of another, the one inside is first
calculated.
Examples: (6-2)X5+8=4X5+8=20+8=28
6X(4+7)+22=6X 11 -22=66+22=3
2+[1OX6(8+2)-4]X2=2+[1OX6Xl0-4]X2
=2+[600-4]X2=2+596X2=2+1192=1194
The parentheses are considered as a sign of multiplication; for example, 6(8 + 2) = 6 x (8 + 2).
The line or bar between the numerator and denominator in a fractional expression is to be considered
as a
division sign. For Example,
In formulas the multiplicationsign
(X) is often left out between symbols or letters, the values of which are to be
multiplied.
Thus
ABC
AB=AXB,and-= (AXBXC)+D
D
Inspector's Handbook

Ratio And Proportion
The ratio between two quantities is the quotient obtained by dividing the first quantity by the second. For
example, the ration between
3 and 12 is
'14, and the ratio between 12 and 3 is 4. Ratio is generally indicated P - *
sign (:); thus 12 : 3 indicates the ratio of 12 to 3.
d
A reciprocal or inverse ratio is the reciprocal or the original ratio. Thus, the inverse ratio 5 : 7 is 7 : 5.
In a compound ratio each term is the product of the corresponding terms in two or more simple ratios.
Thus when
then the compound ratio is:
Prop is the equality of ratios.
Thus,
The first and last
tenns in a proportion are called the extremes; the second and thirds, the means. The
product of the extremes is equal to the product of the means. Thus,
If third terms in the proportion are known, the remaining term may be found by the following rules:
1) The first term is equal to the product of the second and third terms, divided by the fourth term.
2) The second term is equal to the product of the first and fourth terms, divided by the third.
3) The third term is equal to the product of the first and fourth terms, divided by the second.
4) The fourth term is equal to the product of the second and third tenns, divided by the first.
Inspector's Handbook

Calculation of Area
Square/Rectangle = Length * Width
Circles - - w2
Triangle = Height * Base * 1/2
Sphere - - 4m2
Weld Area Calculation
Structural Welds = Length * Width (measured)
Piping Welds
= Circumference
(OD*7t) * Width
Socket Welds
=
LxW
L= ((OD at A+ OD at B) / 2) *7t
W = Width of the weld is measured.
Common Symbols and Terms
3.1415
Diameter / 2
Inside Diameter
Outside Diameter
Less Than (ie 6~9)
Greater Than (ie 9>6)
Equal To or Less Than
Equal To or Greater Than
Plus or Minus
InspectaPs Handbook

Change percent (%) to decimal (0.0) .
Move decimal point 2 spaces to the left and drop the percent sign.,
Example:
2% = 2.0% =
-02 d
Change decimal (0.0) to percent (%) . . .
Move decimal point 2 units to the right and add the percent sign.
Example:
.43 = 43%
Change a fraction to a decimal.
Divide the numerator
by the denominator.
Example:
1/2 = 1 divided by 2 =
.5
Tm = Material Thickness, thickness of the thinner member
excluding reinforcements.
Ts
= Specimen Thickness, thickness of the thinner member
including reinforcements.
Minimum Weld Throat Thickness
=
.7 x Tm
Based upon 1T X 1T
Inspector's Handbook

Solution of Right-angled Triangles

Basic Illustration of a Weld
FILLET LEG
SIZE OF WEW
1qxctoP"s Handbook

Welding Processes ha
ELECTRODE COVERING
Shielded Metal Arc Welding (SMAW)
An arc welding process, which melts and
b
,ins metals by heating them with an arc
oetween a covered metal electrode and the
work. Shielding gas is obtained from the
electrode outer coating, often called
flux.
METAL AND SLAG
Commonly referred to as
"stick" welding.
SOLIDIFIEL) SLAG
SHELDINGGASIN ON
WELD
CURRENT CONDUCTOR
WIRE GUIDE
DIRECTION AND CONTACT
Gas Metal Arc Welding (GMAW)
OF WELDING An arc welding process, which joins metals by heating them
GAS NOZZLE with an arc. The arc is between a continuously-fed filler metal
(consumable) electrode and the mrk piece. Shielding gas is
supplied from an external source of inert
gas, normally argon,
helium, or
a mixture of the two. Commonly referred to as
"MIG" welding.
joins metals by heating them
with an arc
WIRE GUIDE 6. between a continuous, consumable electrode
CONTACT TUBE
wire and the work Shielding is obtained from a
flux contained within the electrode core.
Depending upon the
type of flux-cored wire,
added shielding may or may not
be provided
from externally supplied gas or gas mixture.
tungsten electrode, which should not become part of
the
L
*ompleted weld. Filler metal is normally used when welding.
Jsually helium or argon, or mixture, is used for shielding gas.
Inspector's
Handbook 1-1 1

Backing Ring Common Defect Locations
CRACKING
OVERLAP SLAG/OXIDE INCLUSIONS i

u
UNDERCUT TUNGSTEN INCLUSIONS
POROSITY INCOMPLETE (LACK OF) FUSION
I
CRACKING
BURN-THROUGH
Consumable Insert Common Defect Locations
/
INCOMPLETE (LACK OF) PENETRATION
SLAG OR UNDERCUT AT
THE ROOT
TOES
CRACKING
OVERLAP
SLAG/OXIDE INCLUSIONS
UNDERCU
INcLuSroNS INCOMPLETE (LACK OF) FUSION
POROSITY
I
CRACKING
BAD FITUP
SLAG BETWEEN BACKING
RING
AND PIPE ID
u
CONCAVITY MELT-THROUGH
BURN-THROUGH INCOMPLETE (LACK OF) FUSION 4
UNDERBEAD CRATERS CENTERLINE CREASE
OVERLAP CRACKING
UNDERCUT
AT
THE#OO&OTTO#
BACKING GAS LOS A% MPLETE (LACK OF) PENETMTION
CRACKING
MELT-THROUGH

Hot Tear
Primary Processing Discontinuities
I
Difference in cooling rates between thin sections
and thick sections 1 surface I
Location
Surface
Caused By
Lack of hion between two intercepting surfaces
of metal as it flows into the cast
Process
:L
Casting
I
Porosity I
Entrapped internal gasses
Discontinuity
Cold Shut
Blow Holes
Cavity
Microshrinkage
Inability of external gasses to escape hm the
mold
Forging
I
I
Flattening and lengthening of discontinuities
L sdgem (bar found in parent material ( Subsurface I
Lack of enough molten metal to fill the space
created by shrinkage
Improperly designed mold causing premature
blockage at the mold gate
Surface
I
Laminations (flat plate)
Lengthening of surface cracks found in parent
I Surface
I
Subsurface
Subsurface
Lap
Burst
Flattening and lengthening of discontinuities in
parent material I Subsurface (
FrILaCkof Fusion I Incomplete weld I
Surface
(inner and outer)
Folding of metal in a
thin plate on the
surface of
the forging
Forging at improper temperature
Surface
Surface or
Subsurface
Seams
pipe
I
Present in the parent material (round bar stock)
Laminations
Gouges
Seamless
Pipes and
Tubes
I
Sizing mandrel dragging
Present in the parent material (sheet or parent
material)
1-
Seams
Subsurface
Slugs
Present in parent material ( Surface 1
Porosity ( Present in parent material
,
Metal buildup on piercing material
Inner
Surface
Inspector's
Handbook 1- 13
I
I
w
1
Galling (cracks) Improper metal flow through the die Surface

I Heat Treating
Finish Processing Discontinuities
Explosive
Forming
Process
Grinding
Welding
Stress Cracks
Discontinuity
Cracks
Cracks and Tears
Crater Cracks
(star,
transverse, and
longitudinal)
Caused By
Excess localized heat created between the
grinding wheel and the material
Stress Cracks
Location
Surface
.-/
- -
Porosity
Slag Inclusions
Tungsten Inclusions
I
Lack of Penetration
Lack of Fusion
Undercut
Overlapping I
Extreme deformation overstresses the material I surface
I
~ -
Stress built up by improper processing - unequal
heating and cooling
Improper use of heat source
Surface
Surface or
I Subsurface I
Entrapped gasses
Stresses built up by the weld contraction
(if
material is restrained)
Surface or
I Subsurface
Surface
Excessive current
used during GTAW
Incomplete cleaning of slag
fiom the weld
between passes
I Subsurface I
Surface or
Subsurface
Improper welding technique
Surface or
I Subsurface I
Improper welding technique Subsurface 1
Improper welding technique I surface (
Weld overlaps parent material - not bed I surface
I
I Bending Cracks I
- -
Overstress of material
I Machining 1 Tears I Working with dull tools or cutting too deep 1 Surface I
I Pz?," I Cracks
1 Electroplating
I
Cracks
Inspector's Harrdbook
Relief of internal stress
Relief of internal stress
Surface
Surface

Dial Indicating Calipers
1. VerifL the caliper's calibration date is current, and clean all dirt fiom measuring faces. Perform user
calibration on dial indicator, ensure reading is zero, and tighten the bezel clamp as needed.
2. Adjust measuring faces, contact points, to fit item being measured.
3. Apply
fm pressure to fine adjusting roll and ensure measuring contacts are in contact with the material
being measured.
4. Apply lock screw and read measurement in place if practical. If not, remove calipers carefully to prevent
false measurements.
Micrometer
PART TO BE MEASURED
GRADUATIONS
TO BE READ
FRAME
READING LINE
1.
Verifj. that the micrometer's
calibration date is current, and clean
all
dirt
from measuring contacts. VEPN~ER
C
.000/
GIRHRT/ONS
IS
2. Attach ball if measuring curved
surfaces.
3. Adjust micrometer to fit the item
s-L f CYrC
being measured, do not spin frame to - too 4%vo. Olb
GRRDVRT/O/YS
adjust the micrometer.
4. Slip the micrometer over the area to be measured by placing the anvil fdy against the material and slowly turn
the thimble clockwise until spindle is firmly against the material. Then turn the ratchet three clicks to be sure equal
pressure is applied.
5. Take reading in place, or set the locking nut and remove
fiom the item. Determine reading on scale and note
w
accordingly. Do not forget to minus the ball measurement if used.
Inspector's Handbook

AXIS
PITCH
DIAMETER
Tap and Drill Size Chart
7
THREAD
1 SIZE
CREST
Rm
Inspector's Handbook

Inspector's Handbook 1-17
"w
L'
L
Day
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Dec
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
Nov
305
306
307
308
309
310
311
- 312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
Oct
274
275
276
277
278
279
280
281
-
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
Sep
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
(Perpetual)
Aug
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238 239
240
241
242
243
July
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
Date Calendar
June
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
Julian
May
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
Apr
091
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
I13
114
115
116
117
118
119
120
Mar
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
Feb
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
Day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26 27
28
29
30
. 31
Jan
001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031

1-18 Inspector's Handbook
Day
1
2
3
4
5
6
7
8
9
I0
I1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Jan
001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
Feb
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
Mar
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
Apr
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
Julian
May
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
Date Calendar
June
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
(Leap
July
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
Year)
Aug
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
Sep
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
Dec
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
Oct
275
276
277
278
279
280
281
282
283
284
285 286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
Nov
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
i
C
1 *
2
3
4
5
6
7
8
9
I0
I1
12
13
14
15 '
lb,
v
17
18
19
20
21
22
23
24
25
26
27
28
29
30
3.
4

Chapter 2 - Visual Inspection
Common Definitions and Examples
r Aligned rounded indications
i/
Four or more indications in a line, where each is separated
from the adjacent indication by less then 1/16 inch or
D, whichever
is greater, where
D is the major diameter of the larger of the adjacent
indication. Arc strike
Any localized heat-effected zone or change in the contour of
the surface of the finished weld or adjacent base metal resulting from
m atc or heat generated by the passage of electrical energy between
the surface of the finished weld or base metal and a current source,
such
as welding electrodes or magnetic particle inspection prods.
Burn
throu~h
A void or open hole that extends through a backing ring, strip, fused root, or adjacent base metal.
Burst
A rupture caused by forging at improper temperatures. Bursts may be either internal or external to the
surface.
Cold shut
The result of pouring metal over solidified metal.
/
Track or tear
+
A linear rupture of metal under stress.
Crater pit
An approximately circular surface condition exceeding into
the weld in an irregular manner caused by insufficient filler metal at
the weld stop.
Defect
One or more flaws whose aggregate; size, shape, orientation,
location, or properties do not meet the specified acceptance criteria
and are rejectable.
Discontinuity
Any interruption in the normal physical structure or
configuration of a part, which will cause a detectable indication or
signal when nondestmctively examined.
Evaluation
A review, following interpretation of the indications noted, to determine whether they meet specified
cceptance criteria.
L
Inspector's Handbook 2-1

False indication
An indication that is interpreted to be caused by a condition other than a discontinuity or imperfection.
Heat checks
Fissures or tears in the weld heat affected zone of material containing low melting point.
Indicatic
I
ure of quality characteristic from its intended condition.
Ln
Zvidence of a discontinuity that requires interpretation to determine its significance.
ete fusion I
,ack of complete fusion of some portion of the metal in a
Weld jolnt with adjacent metal. The adjacent metal may be either
base metal or previously deposited weld metal, or consumable insert.
Incomplete penetration
Lack of penetration of the weld through the thickness of the
joint, or penetration which
is less than specified.
Interpretation
The determination of whether indications are relevant,
nonrelevant, or false.
Lap (forginas)
Folding of metal on the surface of the forging, usually occ ' u
when some of the forging metal is squeezed out between the two dies.
Linear indication
An indication in
whichthe length is equal to or
greater
than three times the width.
Melt through
A convex or concave irregularity on the surface of a backing ring or strip, fused root, or adjacent base metal
resulting from fusion completely through a localized region but without development of a void or open hole.
Non-linear rounded indications
Indication whose length is less
than three times its width.
Nonrelevant indications
An indication that is caused by a condition or type of discontinuity that is not relevant.
Inspector's Handbook

Oxidation
A condition resulting from partial or complete lack of inert gas shielding of a surface which is heated
ring welding resulting in formation of oxide on the surface. This condition may range fiom slight oxidation
idenced
by a multicolored or tightly adhering black film to the extreme of a very rough surface having a
crystalline appearance.
Porosity
Gas pockets or voids in weld metal or castings.
Quench crack
A crack formed as a result of the& stresses produced by
rapid cooling fiom a high temperature.
Root surface concavity
A depression on the root surface of a weld which may be due
to gravity, internal purge, or shrinkage.
Root surface centerline crease or shrinkage
An intermittent or continuous peripheral centerline concavity formed on the root surface.
Root undercut
A groove in the internal surface of a base metal or
backing ring or strip along the edge of the root of the
weld.
Shrinkage
Void, or voids, that
may occur in molten metal due to
contraction during solidification.
s&
Non-metallic solid material entrapped in the weld metal,
between weld metal and base metal, or in a casting.
Tungsten inclusion
Tungsten
entrapped in the weld deposit.
Undercut
A groove melted into the base metal at the toe of the weld and
left unfilled by weld metal.
Unfused chaplet
A metal support used in the casting process, which has not
fused with casting material.
Weld spatter
Metal particles which deposit on the surface of the weld or
adjacent base metal during welding and which do not form a part of
the weld.
Inspector's Handbook

Inspector's Handbook

Chapter 3 - Liquid Penetrant Testing
Common Terms and Definitions
Alkaline
L Any soluble mineral salt or mixtures of salt capable of neutralizing acids.
Angstrom Unit (A)
A unit of length equal to lo8 cm and used to express wavelengths of light; i.e., electromagnetic radiation.
Background
The surface upon which an indication is viewed. It may
be the natural surface of the test article or it may be
the developer coating on the surface. This background may contain traces of
unremoved penetrant (fluorescent or
visible), which, if present, can interfere with the visibility of indications.
Background Fluorescence
Fluorescent residues observed over the general surface of the test article during fluorescent penetrant
Eh
Term used colloquially to designate the liquid penetrant inspection materials into which test articles are
immersed during inspection process.
Black Li~ht
Light radiation in the near ultraviolet range of wavelengths (3200 to 4000 A), just shorter than visible light.
Black Light Filter
L A filter that transmits black light while suppressing visible light and hard ultraviolet radiation with
wavelengths less than 3200 angstroms.
Bleedout
The action of the entrapped Penetrant in spreading out from surface discontinuities to form an indication.
Blotting
The action of the developer
in soaking up the entrapped penetrant from dace discontinuities to form an
indication.
Capillary Action or Capillarity
The tendency of liquids to penetrate or migrate into small openings such as cracks, pits, or fissures.
Carrier Fluid
(Vehicle or Medium)
A fluid in which liquid penetrant inspection materials
are dissolved or suspended.
Clean
Free
from interfering solid or liquid contamination on the dace.
Comparative Test Block
An intentionally cracked metal block having two separate but adjacent areas for the application of different
penetrants so that a
d<ect comparison of their relative effeativeness can be obtained. Can also be used to evaluate
?enetrant test techniques and test conditions.
Inspector's
Handbook

Contact Emulsifier
An emulsifier that begins emulsifying penetrant upon simple contact with the penetrant; usually oil-base
(Lipophilic).
Contrast w
The difference in visibility (brightness or coloration) between an indication and the surrounding surface.
Dark Adaptation
The adjustment of the eyes
when one passes from a bright to a darkened area.
Detergent Remover
A penetrant remover that is a solution of a detergent in water. Also
Hydrophilic Emulsifjer.
Developer
A material that is applied to the test article surface after excess penetrant
has been removed and that is
designed to enhance the penetrant
bleedout to form indications. The developer may be a fine powder, a solution
that dries to a fine powder, or a suspension
(in solvent, water, alcohol, etc.) that dries leaving an absorptive film on
the test surface.
Developing Time
The elapsed time necessary for the applied developer to bring out indications from penetrant entrapments.
Also called Development Time.
Dragout
The canput or loss of penetrant materials as a result of their adherence to the articles being processed.
Drain Time w
That portion of the penetrant inspection process during which the excess penetrant, emulsifier, detergent
remover, or developer
is allowed to drain
fiom the test article.
Dry Developer
A fine,
dry powder developer that does not employ a carrier fluid.
Drying Oven
An oven used for drying test articles.
Drvinn Time
A time allotted for a test article to dry.
DuaLresponse Penetrant
A penetr- that contains a combination of visible and fluorescent dyes.
Dwell Time
The total time that the penetrant or emulsifier is in contact with the test surface, including the time required
for application and the
drain time. Also see Emulsification Time.
Electrostatic
Spraying
A technique of spraying wherein the material being sprayed is given a high electrical charge while the test
axticle is grounded. u
Inspector's Handbook

Emulsification Time
The period of time that an emulsifier is permitted to combine with the penetrant prior to removal. Also
called Emulsifier Dwell Time.
Tmulsifier
'v
A liquid that combines with an oily penetrant to make the penetrant water-washable. Also see Hydmphilic
Emulsifier &d Lipophilic Emulsifier.
Flash Point
The lowest temperature at whicha volatile, flammable liquid will give off enough vapor to make a
combustible explosive
mixture in the air space surrounding the liquid surface.
Fluorescence
The
emission of visible radiation by a substance as a result of, and only during, the absorption of black light
radiation.
Fluorescent Dye Penetrant
An inspection penetrant that is characterized by its ability to fluoresce when excited by black light.
Halogen
(Halonenous)
Any of four very active nonmetallic elements; chlorine, iodine, fluorine and bromine.
Hydrophilic Emulsifier
A water-base agent that, when applied to an oily penetrant, renders the penetrant water-washable. Can be
used as a Contact Emulsifier, but more often the emulsifier is added to the water rinse and accompanied by some
form of mechanical agitation or scrubbing to remove excess penetrant. Sometimes called a Hydrophilic Scrubber.
- ~eak Testing
A technique of liquid penetrant testing in which the penetrant is applied to one side of the surface while the
other side is
inspected for indications that would indicate a
through- leak or void.
Lipophilic Emulsifier
An oil-base agent that, when applied to an oily penetrant, renders the penetrant water-washable. Usually
applied
as a Contact Emulsifier.
Near Surface Discontinuity
A discontinuity not open to, but located near, the surface of a test article.
,Nonaqueous Wet Develowr
A developer in which the developing powder is applied as a suspension in a quick-drying solvent. Also
called Solvent Developer.
Penetrability
The property of a penetrant that causes it to find its way into very fine openings, such as cracks.
Penetrant
A liquid (sometimes gas) capable of entering discontinuities open to the surface, and which is adapted to
the inspection process by being made highly visible in small traces. Fluorescent penetrants fluoresce brightly under
black light while the visible penetrants are intensely colored to
be noticeable under visible light.
L
Inspector's Handbook

Post-emulsification Penetrant
A penetrant that requires the application of a separate emulsifier to render the surface penetrant water-
washable. Also can be removed by applying a solvent remover.
Precleaning 4
The removal of surface contaminants or smeared metal from the test article so that they cannot interfere
with the penetrant inspection process.
Ouenchin~ of Fluorescence
The extinction of fluorescence by causes other than removal of black light (the exciting radiation).
Resolution
The property of
a test system that enables the separation of indications of close proximity in a
test article..
Rinse -
The process of removing liquid penetrant inspection materials from the surface of an article by washing or
flooding
with another liquid-usually water. Also called Wash.
See- ability
The characteristic of an indication that enables
th: observer to see it against the conditions of background,
outside light, etc.
Self-developinn Penetrant
A penetrant not requiring the use of a developer. Useful for production work in the detection of gross
discontinuities.
Sensitivity
.'v
The ability ofthe penetrant process to detect minute surface discontinuities.
Solvent Removed
A penetrant-removal technique wherein the excess penetrant is washed or wiped
from the test surface with
a solvent remover.
Solvent Remover
A volatile liquid used to
remow excess surface penetrant from the test article. Sometimes called Penetrant
Remover.
Surface Tension
That property of liquids which, due to molecular forces, tends to bring the contained volume into a form
having the least superficial area.
Viscosity
The state or degree of being viscous. The resistance of a fluid to the motion of its particles.
Visible Dye Penetrant
An inspection penetrant that is characterized by its intense visible color-usually red. Also called Color
Contrast or Nonfluorescent Penetrant.
Water-soluble Developer
A developer in which the developer powder is dissolved in a water carrier to form a solution. Not a
d
suspension.
3-4 Inspector's Handbook

Water-suspended Particle Developer
A developer in which the developer particles are mixed with water to firm a suspension.
Water-wash
L
A penetrant-removal technique wherein excess penetrant is washed or flushed from the test surface with
water.
Water-washable Penetrant
A type of penetrant that contains its own emulsifier, making it water-washable.
Water Tolerance
The amount of water that a penetrant, emulsifier, or wet developer can absorb before its effectiveness is
impaired.
Wet Developer
A developer
in which the developer powder is applied as a suspension or solution in a liquid-usually water
or alcohol.
Wetting Ability
The ability of a liquid to spread out spontaneously and adhere to the test article's surfaces.
Inspector's
Handbook

w
(MAX # OF INDICATIONSl36) X ACTUAL AREA = NEW MAX # OF INDICATIONS
I
-
I .I00 .0079
Area = m2
Inspector's Handbook

Penetrant Wetting Characteristics
Inspector's HandGook

Inspector's Randbook

Chapter 4 - Magnetic Particle Testing
Common Definitions and Examples
-.& gap
When a magnetic circuit contains a small gap, which the magnetic flux must cross, the space is referred to
as an
air gap. Cracks produce small air gaps on the surface of an article.
Alternating current
Electric current periodically reversing in polarity or direction of flow.
AmDere
The unit of electrical current. One ampere is the current that flows through a conductor having a resistance
of one ohm at a potential of one volt.
Ampere turns
The product of the number of
turns in a coil and the number of amperes flowing through it. A measure of
the magnetizing or demagnetizing strength of the coil. Wh
The suspension of iron oxide particles in a liquid vehicle (light oil or water).
J
Black light
Radiant energy in the near ultraviolet range. This light has a wavelength of 3200 to 4000 angstrom units
(A), peaking at
3650 A, on the spectrum. This between visible light and ultraviolet light.
$lack light filter
A filter that transmits black light while surprising the transmission of visible light and harrml ultraviolet
radiation.
Carbon steel
Steel that does not contain significant amounts of alloying elements other
than carbon and
maganese.
Carrier fluid
The fluid in which fluorescent and no* fluorescent magnetic particles are suspended to facilitate their
application
in the wet method.
Central conductor
An electrical conductor that is passed through the opening in a ring or tube, or any hole in an article, for the
purpose of creating a circular field in the ring or
tube, or around the hole.
Circular field
See Field, Circular Magnetic.
Circular magnetization
A method of inducing a magnetic field in an article so that the magnetic lines of force take the form of
concentric rings about the axis of the current. This is accomplished by passing the current directly through the
article or through a conductor which passes into or through a hole in the article. The circular method is applicable
for
th detection of discontinuities with axes approximately parallel to the axis of current through the article.
Inspector's Handbook

Coercive force
The reverse magnetizing force necessary to remove residual magnetism in demagnetizing an article.
Coil shot
A pulse of magnetizing current passed through a coil surrounding an article for the purpose of
longid -
magnetization.
Contact headshot
The electrode, faed to the magnetic particle testing unit, through which the magnetizing current is drawn.
Contact pads
Replaceable metal pads, usually of copper braid, placed on contact heads to give good electrical contact
thereby preventing damage to the article under test.
1
Continuous method
An inspection method in which ample amounts of magnetic particles are applied, or are presa on the
piece, during the time the magnetizing current is applied.
Core -
That part of the magnetic circuit that is within the electrical winding.
Curie point
The temperature at which ferromagnetic materials can no longer
be magnetized by outside forces, and at
which they lose their residual magnetism: approximately 1200 to
1600' F (646 to 871° C) for many metals.
Current Flow Technique
A technique of circular magnetization in which current is passed through an article via prods or contact
4
heads. The current may be alternating, half- wave rectified, rectified alternating, or direct.
Cmt Induction Technique
A technique of magnetization in which a circulating current is induced in a ring-shaped component by a
fluctuating magnetic field.
Demamethtio n
The reduction in the degree of residual magnetism to an acceptable level.
Diamagnetic
Materials whose atomic structure won't permit any real magnetization. Materials such
as bismuth and
copper are diamagnetic.
Diffused Indications
Indications that are not clearly defined, such as indications of subsurface defects.
Direct Contact Magnetization
A magnetic particle testing technique in which current is passed
throdgh the test article. These include
headshots and prod shots.
Direct Current
An electrical current, which flows steadily in one direction
4-2 Inspector's
Handboak

Distorted Field
A field that does not follow a straight path or have a uniform distribution.
This occurs in irregularly shaped
objects.
b
Dry Medium
Magnetic particle inspection
in which the particles employed are in the dry powder
fom
Dry Powder
Finely divided ferromagnetic particles suitably selected and prepared for magnetic particle inspection.
Electromagnet
A magnet created by inserting a suitable metal core within or near a magnetizing field formed by passing
electric current through a coil of insulated wire.
Etching
The process of exposing subsurface conditions of metal articles by removal of the outside surface through
the use of chemical agents. Due to the action of the chemicals in eating away the surface, various surface or
subsurface conditions are exposed or exaggerated and made visible to the eye.
Ferromagnetic
A term applied to materials that can be magnetized and strongly attracted by a magnetic field.
Field, Circular
Mametic
Generally the magnetic field in and surrounding any electrical conductor or article resulting from a current
being passed through the conductor or article or fiom prods.
.field, Longitudinal Magnetic
A magnetic field wherein the flux lines traverse the component in a direction essentially parallel with the
axis of the magnetizing coil or to a line connecting the two poles at the magnetizing yoke.
Field, Magnetic
The space within and surrounding a magnetized article, or a conductor carrying current
in which the
magnetic force is present.
Field, Magnetic
Leakwe
The magnetic field that leaves or enters the surface of an article at a magnetic pole.
Field. Multidirectional
A magnetic field that is the result of two magnetic forces impressed upon the same area of a magnetizable
object at the sametime-sometimes called a "vector field."
Field, Residual
Mametic
The field that remains in magnetizable material after the magnetizing force has been removed
Flash Magnetization
Magnetization by a current flow of very brief duration.
Fluorescence
W ,J The emission of visible radiation by a substance as the result of and only during the absorption of black
light radiation.
Inspector's Handbook

Fluorescent Magnetic Particle Inspection
The magnetic particle inspection process employing a finely divided fluorescent ferromagnetic inspection
medium that fluoresces when activated by black light.
V
Flux Density
The normal magnetic flux per unit area It is designated by the letter "B" and is expressed in telsa (SI units)
or gauss (cgs
units).
Flux Leakage
Magnetic lines of force which leave and enter an article at poles on the surface.
Flux Lines
Imaginary magnetic lines used as a means of explaining the behavior of magnetic fields. Their conception
is based on the pattern of lines produced when iron filings are sprinkled over a piece of paper laid over a
permanent magnet. Also called Lines of Force.
Flux Penetration, Magnetic
The depth to which a magnetic flux is present in
an article.
Furring
Buildup or bristling of magnetic particles due to excessive magnetization of the article.
Gauss
The unit of flux density. Numerically, one gauss is one line of flux per square centimeter of area and is
designated by the letter "B."
-
w
Head Shot
A short pulse of magnetizing current passed through
an article or a central conductor while clamped
between the head contacts of a stationary magnetizing unit for the purpose of circularly magnetizing the article.
Heads
The clamping contacts on a stationary magnetizing unit.
Horseshoe Magnet
A bar magnet bent into the shape of a horseshoe so that the two poles are adjacent. Usually the term applies
to a permanent magnet.
Hysteresis
The lagging of the magnetic effect when the magnetic force
acting upon a ferromagnetic body is changed;
the phenomenon exhibited by a magnetic system wherein its state is influenced by its previous magnetic history.
Hysteresis
Loop
A curve showing the flux density, "B," plotted as a
hction of magnetizing force, "H." As the magnetizing
force is increased to the saturation point
in the positive, negative, and positive direction sequentially, the curve
forms a characteristic S-shaped loop. Intercepts of the loop with the "B" and "H" axes and the points of
maximum
and minimum magnetizing force define important magnetic characteristics of the material.
Inductance
w
The magnetism produced in a ferromagnetic body by some outside magnetizing force. The magnetism is
not the result of passing current through the article.
4-4 Inspector's
Randbook

Leakage Field
The magnetic field forced out into the
air by the distortion of the field within an article.
',ifit Intensitv
L
. , The light energy reaching a unit of surface area per of time.
Lonnitudinal Magnetization
The process of inducing a magnetic field into the article such that the magnetic lines of force extending
through the article are approximately parallel to the axis of the magnetizing coil or to a line connecting the two
poles when yokes (electromagnets) are used.
Magnet, Permanent
A highly-retentive metal that has been strongly magnetized;
i.e., the alloy Alnico.
Mmetic Field Indicator
An instrument designed to detect andlor measure the flux density and polarity of magnetic fields.
Magnetic Field Strength
The measured intensity. of a magnetic field at a point always external to the magnet or conductor; usually
expressed
in amperes per meter or oersted (Oe).
Magnetic Material
Those materials that
are attracted by magnetism.
Magnetic Particles
Finely divided ferromagnetic material.
i/
Magnetic Particle Inspection
A nondestructive inspection method for locating discontinuities in ferromagnetic materials.
Magnetic Poles
Concentration of
flux leakage in areas of discontinuities, shape changes, permeability variations, etc.
Magnetic Writing
A form of nonrelevant indications caused when the
suface of a magnetized part comes in contact with
another
piece of ferromagnetic material that is magnetized to a different value.
Magnetizing Current
The flow of either alternating, rectified alternating, or direct current used to induce magnetism into the
article being inspected.
Magnetizin~ Force
,The magnetizing field applied to a ferromagnetic material to induce magnetization.
Medium
The fluid in which fluorescent and nonfluorescent magnetic particles are suspended to facilitate their
application
in the wet method.
b Jear Surface Discontinuitv
A discontinuity not open to, but located near, the surface of a test article.
Inspector's
Handbook

Oersted
A unit of field strength, which produces magnetic induction and is designated by the letter "H."
/
Paramagnetic 4
Materials which are slightly affected by a magnetic field. Examples are chromium, manganese, aluminun,
and platinum. A small group of these materials are classified as ferromagnetic.
Permeability
The ease with which the
lines of force are able to pass
through an article.
Pole -
The area on a magnetized article fiom which the magnetic field is leaving or returning to the article.
Prods
Hand-held electrodes attached to cables used to transmit the magnetizing current from the
source to the
article under inspection.
Rectified Alternating Current
Alternating current, which
has been converted into direct current.
Reluctance
The resistance of a magnetic material to changes
in magnetic field strength.
Residual Magnetism
The amount of magnetism that a magnetic material retains after the magnetizing force is removed. Also
called "residual field" or
"remanence."
w
Residual Technique
A procedure in which the indicating material is applied after the magnetizing force has been discontinued.
Retentivity
The
ability of a
~mterial to retain a certain portion of residual magnetization. Also known as rernanence.
Saturation
The point at which increasing the magnetizing force produces no
Mher magnetism in a material.
Sensitivity
The capacity or degree of responsiveness to magnetic particle inspection.
Settling Test
A procedure used to determine the concentration of magnetic particles in a medium or vehicle.
Skin
Effect
The description given to alternating current magnetization due to its containment to the surface of a test
article.
Solenoid (Coil)
An electric conductor formed into a coil often wrapped around a central core of highly permeable mate
,,
4-6 Inspector's Handbook

Suspension
The correct term applied to the liquid bath in which the ferromagnetic particles used in the wet magnetic
particle inspection method &e suspended.
>
Lrest Article
An article containing known artificial or natural defects used for checking the efficiency of magnetic
particle flaw detection processes.
Wet Medium
An inspection employing ferromagnetic particles suspended in a liquid (oil or water) as a vehicle.
Yoke
A
U-shaped or C-shaped piece of highly permeable magnetic material, either solid or laminated, sometimes
with adjustable pole pieces (legs) amund which is wound a coil carrying the magnetizing current.
Yoke Magnetization
A
longitudinal magnetic field induced in an article or in an area of an article by means of an external
electromagnei shaped like a yoke.
Longitudinal Magnetization Math Formula
45,000 (+/- lo?!)
AT
= W)
A = ampere
T = turns of the coil
L = length of the item
D = diameter or cross section of the item
The
minimum
UD ratio is 2
The maximum L used in calculations is 20 inches
Inspector's
Handbook 4-7

Common Types of Magnetization
Central Conductor (circular) Horse shoe (longitudinal)
Coil Shot (longitudinal)
Yoke (longitudinal)
Discontinuities
Theory: "Right-Hand Rulen
CURRENT
FLOW
Inspector's Handbook

Hysteresis Curve
B+ (FLUX DENSITY)
0 - A = Referred to as the virgin curve
L/
A = Saturation point
-
B = Residual field
0 - C = Coercive force
D = Reverse saturation point
E
= Reverse residual field 0 - F = Reverse coercive force
H- (MAGNETIZING FORCE OF
OPPOSITE POLARITY TO H+) H= (MAGNETIZING FORCE)
R (FLUX DENSITY OF
OPPOSITE POLARITY TO
B+)
SLENDER LOOP
WIDE LOOP
HIGH PERMEABILITY LOW PERMEABILITY
LOW RENTENTIVITY HIGH RENTENTMTY
LOW COERCIVE FORCE HIGH COERCIVE FORCE d
LOW RELUCTANCE HIGH RELUCTANCE
LOW RESIDUAL MAGNETISM HIGH RESIDUAL WU3FETISM
Inspector's Hadbook

Magnetic Particle Field Indicator (Pie Gage)
Eight low carbon steel pie
sections, furnace brazed
Artificial flaw (all segment
1 in. interfaces)
,' I '
I'
I
Nonferrous handle of any
/J
Convenient length
Copper plate
0.010 in t 0.001 in
thick 7
Braze weld or mechanically
I

attach nonferrous trunnions
Inspector's
Handbook

Inspector's Hanetbook

Chapter 5 - Ultrasonic Testing
Common Terms and Definitions
-\-scan Display
A dimlav in which the received signal is displayed as a vertical displacement fiom the horizontal sweep
time trace, wkl; the horizontal distance between a& Go signals represents the sound path distance (or time of
travel) between the two.
Absorption Coefficient, Linear
The fractional decrease in transmitted intensity per unit of absorber thickness. It is usually designated by
the symbol and expressed
in units of
cml.
Acceptance Standard
A control specimen containing natural or artificial discontinuities that are well defined and, in size or
extent, similar to the
maximum acceptable in the product. Also may refer to the document defining acceptable
discontinuity size limits.
Acoustic Impedance
The factor which controls the propagation of an ultrasonic wave at a boundary interface. It is the product of
the material density and the acoustic wave velocity
within that material.
Amplifier
A device to increase or amplify electrical impulses.
Amplitude. Indication
b. The vertkal height of a received indication, measured fiom base-to-peak or peak-to-peak.
Angle
Beam Testing
A testing method in which
trammission is at an angle to the sound entry surface.
Amle of Incidence
The angle between the incident
(transmitted) beam and a normal to the boundary interface.
Angle of Reflection
.
The angle between the reflected beam and a normal to the boundary interface. The angle of reflection is
equal to the angle of incidence.
Angle of Refraction
The angle
between the refracted rays of an ultrasonic beam and the normal (or perpendicular line) to the
rehcting surface.
Angle Transducer
A transducer that transmits or receives the acoustic energy at an acute angle to the surface to achieve a
specific effect such up the setting up of shear or surface waves in the part being inspected.
Anisotropic
A condition in which properties of a medium (velocity, for example) vary according to the direction in
,, vhich they are measured.
Inspector's
Handbook

Array Transducer
A transducer made up of several piezoelectric elements individually connected so that the signals they
transmit or receive nay be treated separately or combined as desired.
s-,
Attenuation Coefficient
A factor which is determined by the degree of scatter or absorption of ultrasound energy per unit distance
traveled.
Attenuator
A device for measuring attenuation, usually calibrated in decibels (dB).
B-scan Display
A cathode-ray tube display in which the received signal is displayed as an illuminated spot. The face of the
CRT represents the area of a vertical plane through the material. The display shows the location of
a discontinuity,
as it would appear in a vertical section view through the thickness direction of the material.
Back Reflection
.
The signal received
from the back surface of a test object.
Back Scatter
Scattered signals that are directed back to the transmitterlreceiver.
Background Noise
Extraneous signals caused by signal sources
within the ultrasonic testing system, including the material in
test. w
Barium Titanate (Polycrystalliie Barium Titanate - Barn3)
A ceramic transducer material composed of many individual crystals fired together and polarized by the
application of a dc field.
Baseline
The horizontal line across the bottom of the CRT created by the
sweep circuit.
Basic.Calibration
The procedure of standardizing an instrument using calibration reflectors described in an application
. document.
B i- modal
The propagation of sound
in a test article where at least a shear wave and a longitudinal wave exists. The
operation of angle beam testing at less
than first critical angle.
Boundary Indication
A reflection of an ultrasonic beam from an interface.
Broad Banded
Having a relatively wide frequency bandwidth. Used to describe pulses which display a wide frequency
spectnun and receivers capable of amplifying them.
4
Inspector's Handbook

C-scan
A data presentation method yielding a plan (top) view through the scanned surface of the part. Through
gating, only indications arising from the interior of the test object are indicated.
X/
",libration
To determine or mark the graduations of the ultrasonic system's display relative to a known standard or
reference.
Calibration Reflector
A reflector with a known dimensioned surface established to provide an accurately reproducible reference.
Collimator
An attachment designed to reduce the ultrasonic beam spread.
Compensator
An electrical matching network to compensate for circuit impedance differences.
Compressional Wave
A wave in which the particle motion or vibration is in the same direction as the propagated wave
(longitudinal wave).
Contact Testing
A technique of testing in which the transducer contacts the test surface, either directly or through a thin
layer of
couplant.
Contact Transducer
A transducer which is coupled to a test surface either directly or through a thin film of couplant.
L.
Continuous Wave
A wave that continues without interruption.
Contracted Sweep
A contraction of the horizontal sweep on the viewing screen of the ultrasonic instrument. Contraction of
this sweep
pennits viewing reflections occurring over a greater sound-path distance or duration of time.
Comer Effect
The strong reflection obtained when
an ultrasonic beam is directed toward the inner section of two or three
mutually perpendicular surfaces.
Couplant
A substance used between the face of the transducer and test surface to permit or improve transmission of
ultrasonic energy across this bounw or interface. Primarily used to remove the air in the interface.
Critical An~le
The incident angle of the sound beam beyond which a specific refracted mode of vibration no longer exists.
Cross Talk
An unwanted condition in which acoustic energy is coupled from the transmitting crystal to the receiving
.,pystal without propagating along the intended path through the material.
Ld
Inspector's Handbook

Damping (transducer)
Limiting the duration of vibration in the search unit by either electrical or mechanical means.
Dead Zone
The distance
in a material from the sound entry surface to the nearest inspectable sound path.
4
Decibel (dB)
The logarithmic expression of a ratio of two amplitudes or intensities of acoustic energy
Delamination
A laminar discontinuity, generally an area of
unbonded materials.
Delay Line
A material (liquid or solid) placed in front of a transducer to use a time delay between the initial pulse and
the
fiont surface reflection.
Delayed Sweee
A means of delaying the start of horizontal sweep, hereby eliminating the presentation of early response
data.
Delta Effect
Acoustic energy re-radiated by a discontinuity.
Detectability
The ability of the ultrasonic system to locate a discontinuity.
Difiction
The deflection, or "bending," of a wave front when passing the edge or edges of a discontinuity.
Diffise Reflection
Scattered, incoherent reflections caused by rough surfaces or associate interface reflection of ultrasonic
waves
from irregularities of the same order of magnitude or greater than the wavelength.
Discontinuity
An interruption or change in the physical structure or characteristics of a material.
Dispersion, Sound
Scattering of
an
ultrasonicbeam as a result of diffuse reflection from a highly- irregular surface.
Distance Amplitude Correction PAC)
Compensation of gain as a function of time for difference in amplitude of reflections fiom equal reflectors
at different sound travel distances. Also referred to as time corrected gain
(TCG), time variable gain (TVG) and
sensitivity time control
(STC).
Divergence
Spreading of ultrasonic waves after leaving search unit, and is
a function of diameter and frequency.
Dual-Element Technique
The technique of ultrasonic testing using two transducers with one acting as the transmitter and one as
f .&
receiver.
5-4
Inspector's Handbook

Dual-Element Transducer
A single transducer housing containing two piezoelectric elements, one for transmitting and one for
receiving.
zffective Penetration
The maximum depth in a material at which the ultrasonic transmission is sufficient for proper detection of
discontinuities.
Electrical Noise
Extraneous signals caused by externally radiated electrical signals or from electrical interferences within
the ultrasonic instrumentation.
Electromametic Acoustic Transducer (EMAT)
A device using the magneto effect to generate and receive acoustic signals for ultrasonic nondestructive
tests.
Far Field
The region beyond the near field in which
areas of high and low acoustic intensity cease to occur.
First
Leg
The sound path beginning at the exit point of the probe and extending to the point of contact opposite the
examination surface when performing angle beam testing.
Focused Transducer
A transducer with a concave face which converges the acoustic beam to a focal point or line at a
defd
distance from the race.
LZ
Focusing
Concentration or convergence of energy into a smaller beam.
Frequency
Number of complete cycles of a wave motion passing a given point in a unit time (1 second); number of
- - -
times a vibration is repeated at the same point in the same direction per unit time (usually per second).
Gate -
An electronic means to monitor an associated segment of time, distance, or impulse.
Ghost
An indication which has no direct relation to reflected pulses
from discontinuities in the materials being
tested.
Emz (Hz)
One cycle per second.
Horizontal Linearity
A measure of the proportionality between the positions of the indications appearing on
the baseline and the
positions of their sources.
'Immersion Testing
b
A technique of testing, using a liquid as an ultrasonic couplant, in which the test part and at least the
transducer face is immersed
in the couplant and the transducer is not in contact with the test part.
Inspector's Handbook
5-4

Impedance (acoustic)
A material characteristic defined as a product of particle velocity and material density.
Indication (ultrasonics)
The signal displayed or read on the ultrasonic systems display.
Initial Pulse
The first indication which may appear on the screen. This indication represents the emission of ultrasonic
energy from the crystal face (main bang).
Interface
The physical boundary between two adjacent acoustic mediums.
Insonification
Irradiation with sound.
Isotropy
A condition in which significant medium properties (velocity, for example) are the same in all directions.
Lamb Wave
A
type of ultrasonic vibration guided by parallel surfaces of thin mediums capable of propagation in
different modes.
Linearity (area)
A system response
in which a linear relationship exists between amplitude of response and the
discontinuity sizes being evaluated necessarily limited by the size of the ultrasonic beam.
v
Linearity (depth)
A system response where a linear relationship exists with varying depth for a constant size discontinuity.
Longitudinal Wave Velocity
The unit speed of propagation of a longitudinal (compressional) wave through a material.
Loss of Back Reflection
Absence of or a significant reduction of
an indication
from the back surface of the article being inspected.
Maior Screen Divisions
The vertical graticule used to divide the CRT into 10 equal horizontal segments.
Manipulator
A device used to orient the transducer assembly. As applied to immersion techniques, it provides either
angular or normal incidence and
fmes the transducer-to-part distance.
Material Noise
Extraneous signals caused by the structure of the material being tested.
Miniature Angle Beam Block
A specific type of reference standard used primarily for the angle beam method, but also used for
straig w
beam and surface wave tests.
Inspeetor's Handbook

Minor Screen Divisions
The vertical graticule used to divide the CRT into
fifty equal segments. Each major screen division is
divided into five equal segments or minor divisions.
;Mode Conversion
The change of ultrasonic wave propagation upon reflection or refraction at acute angles at an interface.
Mode
The manner in which acoustic energy is propagated through a material
as characterized by the particle
motion of the wave.
Multiple Back Reflections
Repetitive indications
from the back dace of the material being examined.
Nanosecond
One billionth of a second.
Narrow Banded
A relative term denoting a restricted range of frequency response.
Near Field.
A distance immediately in front of a transducer composed of complex and changing wave front
characteristics. Also known
as the Fresnel field.
Node
The point on the examination surface where the V-path begins or
ends.
L.
L40ise
Any undesired indications that tend to interfere with tk interpretation or processinn of the ultrasonic -
information; also referred to as "grass."
Normal Incidence
A condition where the angle of incidence is zero.
Orientation
The angular relationship of
a surface, plane, defect axis, etc., to a reference
plw or sound entry surface.
Penetration (ultrasonic)
Propagation of ultrasonic energy through an article.
Phased
Array
A mosaic of probe elements in which the timing of the element's excitation can be
individuallv controlled
to produce certain desired effects, such
as steering the beam axis or focusing the beam.
Piezoelectric Effect
The characteristic of certain materials to generate electrical charges when subjected to mechanical
vibrations and, conversely to generate mechanical vibrations when subjected to electrical pulses.
Inspector's Handbook

Polarized Ceramics
Ceramic materials that
are sintered (pressed), created (approximately
100oOc), and polarized by applying a
direct voltage of a few thousand volts
per centimeter of thickness. The polarization is the process that makes these
ceramics piezoelectric. Includes sodium bismuth titanate, lead metaniobate, and several materials based on
lea+
zirconate titanate (PZT).
u
Presentation
The method used to show ultrasonic information. This may include (among others) A-, R, or C-scans
displayed on various types of recorders, CRTs, LCD's or computerized displays.
Probe
Transducer or search unit.
Propagation
Advancement of a wave through a medium.
Pulse Echo Technique
An ultrasonic test technique using equipment which transmits a series of pulses separated by a constant
period of time; e., energy is not sent out continuously.
Pulse
Len*
Time duration of the pulse from the search unit.
Pulse Rate
For the pulse echo technique, the number of pulses transmitted in a unit of time (also called pulse repetition
rate).
..r
Radio Frequency Display (RF)
The presentation of unrectified signals in a display.
i.bxs
The maximum ultrasonic path length that is displayed.
Rarefaction
The thinning out or moving apart of the consistent particles in the propagating medium due to the
relaxation phase of
an ultrasonic cycle. Opposite in its effect to compression. The sound wave is composed of
alternate compressions and
rehctions of the particles in a material.
Raylei& WaveISurface Wave
A wave that travels on or close to the surface and readily follows the curvature of the part being examined.
Reflections occur only at sharp changes of direction of the surface.
Receiver
The section of the ultrasonic instrument that amplifies the electronic signals returning from the test
specimen. Also, the probe that receives the reflected signals.
Reference Blocks
A block or series of blocks of material containing artificial or actual discontinuities of one or more
reflecting areas at one or more distances *om the sound entry surface. These are used for calibrating instrume
and in defining the size and distance of discontinuous areas in materials.
5-8 Inspector's EI.andbook

Reflection
The characteristic of a surface to change the direction of propagating acoustic energy; the retun of sound
3- -res from surfaces.
L
Pehction
A change in the direction and velocity of acoustic energy after it has passed at an acute angle through an
interface between two different mediums.
Refractive Index
The ratio of the velocity of a incident wave to the velocity of the refhcted wave. It is a measure of the
amount a wave
will be refracted when it enters the second medium after leaving the first.
Reiect/Suppression
An instrument function or control used for reducing low amplitude signals. Use of this control may affect
vertical linearity.
Repetition Rate
The rate at which the individual pulses of acoustic energy
are generated; also Pulse Rate.
Resolving Power
The capability measurement of
an ultrasonic system to separate in time two closely spaced discontinuities
or to separate closely spaced, multiple reflections.
Resonance Technique
A technique using the resonance principle for determining velocity, thickness or presence of laminar
L Siscontinuities.
,iesonance
The condition in which the hquency of a forcing vibration (ultrasonic wave) is the same as the natural
vibration frequency of the propagation body (test object), resulting in large amplitude vibrations.
Saturation (scope)
A term used to describe an indication of such a size as to exceed full screen height (100%).
Scanning (manual and automatic)
The moving of the search unit or units along a test surface to obtain complete testing of
a material.
Scattering
Dispersion of ultrasonic waves in a medium due to causes other than absorption
Second
Leg
The sound path beginning at the point of contact on the
opposite surface and extending to the point of
contact on the examination surface when performing angle beam testing.
Sensitivity
The ability to detect small discontinuities at given distances. The level of amplification at which the
receiving circuit in an ultrasonic instrument is set.
Shear Wave
The wave
in which the particles of the medium vibrate in a direction perpendicular to the direction of
propagation.
Inspector's Handbook
5-

Signal- to-Noise Ratio (SNR)
The ratio of amplitudes of indications from he smallest discontinuity considered significant and those
caused by random factors, such
as heterogeneity in grain size, etc.
,
-
u
Skip Distance
In angle beam tests of plate, pipe, or welds, the linear or surface distance from the sound entry point to the
first reflection point on the same surface.
Snell's Law
The law that defines the relationship between the angle of incidence and the angle of refkction across an
interface, based on a range
in ultrasonic velocity.
Specific Acoustic Impedance
A characteristic which acts to
determine the amount of reflection which occurs at an interface and
represents the wave velocity and the product of the density of the medium in which the wave is propagating.
Straight Beam
An ultrasonic wave traveling
normal to the test surface.
Sweep
The uniform and repeated movement of a spot across the screen of a CRT to form the baseline.
Through-Transmission
A test technique using two transducers in which the ultrasonic vibrations are
ernitted by one and received
by the other, usually on the opposite side of the part. The ratio of the magnitudes of vibrations transmitted and
received is used
as the criterion of soundness.
' 4
Tip Diffiction
The process by which a signal is generated from the tip (i.e., top of a fatigue crack) of a discontinuity
through the interruption of
an incident sound beam propagating
through a material.
Transducer (search unit)
An assembly consisting basically of a housing, piezoelectric element, backing material, wear plate
(optional) and electrical leads for converting electrical impulses into mechanical energy and vice versa.
Transmission Angle
The incident angle of the transmitted ultrasonic beam. It is zero degrees when the ultrasonic beam is
perpendicular to the test
swface.
Transmitter
The electrical circuit of an ultrasonic instrument that generates the pulses emitted to the search unit. Also
the probe that emits ultrasonic signals.
Two Probe Method
Use of two transducers for sending
and receiving. May be either send-receive or through
transmission.
Ultrasonic Absorption
A damping of ultrasonic vibrations that occurs when the wave transverses a medium.
Inspector's
Handbook

Ultrasonic Spectrum
The frequency
span of elastic waves greater than the highest audible
kquency, generally regarded as being
higher
than
20,000 hertz, to approximately 1O00 megahertz.
'Jltrasonic Svstem
The totality of components utilized to perform an ultrasonic test on a test article.
V-path
The vath of the ultrasonic beam in the test object from the point of entry on the examination surface to the
back surface' and reflecting to the front surface again.
Velocity
The speed at which sound travels through a medium.
Video Presentation
A CRT presentation in which radio frequency signals nave been rectified and usually filtered.
Water Path
The distance
fnrm the face of the search unit to the entry surface of the material under test in immersion
testing.
Wavelength
The distance
in the direction of propagation for a wave to go through one complete cycle.
Wedgelshoe
A device used to adapt a straight beam probe for use in a specific type of testing, including angle beam or
L
dace wave tests and tests on curved surfaces.
Wraparound
Nonrelevant indications that appear on the CRT as a result of a short pulse repetition rate in the pulser
circuit of the test instrument.
Inspector's
Handbook

Common Math Formulas
Wavelength
L
I
T
5-12 Inspectar's Handbook
r
? = Wavelength
V = Veloocity
F = Frequency
Reflected Acoustic Energy
21-22 ) 2
ER= 100 (-
21 +22
ER = Energy reflected
Z1 = Acoustic impedance material #1
22 = Acoustic impedance material #2
Nearfield (nearzone) u
N =
D * (F)
4 (V)
N = Length of the near field
D
= Diameter of the transducer
F
= Transducer frequency
V = Materials velocity
Crystal Thickness
h
CT =
2
CT = Crystal thickne$s
h = Wavelength
Use .23 if material is unknown
Energy Transmitted
ET = El - ER
ET
= Energy transmitted
El
= Energy
intiated
ER = Energy reflected
Acoustic Impedance
z = POI)
Z = Acoustic impedance
P = Materials density
V = Acoustic velocity
Half Angle Beam Spread
v
SIN 0 = K ()
D*F
K= 1.22
V
= Velocity of the material
D
= Diameter of the transducer
F
= Frequency of the transducer
Times 2 for full angle beam spread
Decibel Difference A1
Db=20 [LOG (-)I
A2
Db = Decibel difference
LOG
= Natural
logrithm
A1 = Amplitude number one
A2 = Amplitude number two
Rule of thumb: every 6 Db doubles the size of the
indication height (pip)
Snell's Law & Angle of Reflection
SIN 01 =
SIN 02 * V1
V2
Angle of incidence
* 1st critical angle V2 is long
= 90°
Critical angle* 2nd critical angle V2 is shear = 90°
Wedge angle
SIN
02 =
'IN
* V2
v1

Half / Full Sound Path & Skip / Setback Distance
T HALF SKIP = T TAN 8
HSP= -
COS 0
2T FULL SKIP = 2T * TAN 0
FSP= -
cos e
T =Member thickness
Surface Distance to Defect / Depth of Defect
SDD = Sound Path * SIN 8 #DD = Sound Path * COS 8
##DD = (Sound Path * COS 0) - 21
SDD Surface distance to defect
#DD =Depth of defed during half sound path
##OD =Depth of defect during full sound path
T =Member thickness
Calibration Chart - UT Shearwave
b
PLATE
THICKNESS *HALF SKIP
1" 112" 314" 1"
PLATE
THICKNESS FULL SKIP
I 1 - 112" 1 - 314" 2"
* Applicable holes in the M.I. block for calibration
Inspector's Handbook

Inspector's Handbook

Velocity Chart
I I I LONGITUDINAL 1 SHEAR I ACOUSTIC 1
Aluminum
Aluminum Oxide
Bertilium
Copper I 8.9 I -18 I .089 I 41.6
Crown Glass 2.5 .21 .I2 18.9
Ice 1 .OO .I6 .08 3.5
,Inconel ---- .22 .I2 47.2
Iron ---- .23 .I3 45.4
2.7
- - - -
1.82
.43
I - - - - I
,#~&~~~;@~$~g+;~~~~$[@:@~,t
KrTnCarbie I ----
Mercurv ---- .057 I - - - - I 19.6
Molvbdenum 1 10.09 1 .25 .I3 64.2
Cadium 8.6 .ll 1 .059 ! 24
, , , - ,*,.,. $> ,.s,,~ v.x< ,,,, ..",
~~~&~'i~$&iia$gfigp&
+
.25
.39
-51
$~f&<gg$-@@#
lOil (SAE 30) I 0.95 1 .067 I ---- 1.5
I
Monel ----
' ,"":G,~w$~.~$s~&-&~. ,, ";?$;>$..p$",2$$2
~~~wp&n8:F~w~;&~k~&iyr.~I-j~.t~~ . . .
Nickel I 8.3
.I 2
.23
.35
Steel, Mild
I 7.7 I .23 I .I3 I 46
,Steel, Stainless I 8.03 1 .23 -12 I 45.4
17
32
23
.21 I -1 1
~%;62%,:*, " ' y,''%~;~~~~ !$%:?>&@&$?& & ,..<::
;&4~;.~~%<~$~&~~i-~f ,6"t*~5-i.&i&+&r.
-22 I .12
Polyethylene
Polvstyrene
Polyurethane
47.6
2@&d@@& ' w'*'",*
;>:'. 5~;,%k.a3g&&g$$
49.5
Inspector's Handbook
- - - -
1.06
----
Titanium
Tungsten
Uranium
.07
.093
.07
4.54
19.25
----
.02
.04
- - - -
.24
.20
.I3
1.7
2.5
1.9
-12
.I 1
.OW
27.3
101
63

Pnspector's Handbook

Chapter 6 - Eddy Current Testing
Common Terms and Definitions
Absolute Coil
b A test arrangement which tests the specimen without any comparison to either another portion of the test
specimen or to a known reference.
Alternating
A voltage, current or magnetic field that reverses direction at regularly recurring intervals.
Bobbin Coil
A coil or coil assembly used for eddy current testing by insertion into the test piece;
e.g., an inside probe
for tubing. Also referred to
as Inside Coil or IP Coil.
Coil
-
Conductor wound in one or more loops to produce an axial magnetic field when current is passed through
it.
Coil Spacing
The axial distance between two encircling coils of a differential system.
Conductivity
/
The willingness of a test circuit or test specimen to conduct current.
Coupling
A measure of the degree to which the magnetic field of the coil passes through the test specimen and is
w ffkted by the magnetic field created by the flow of eddy currents.
Defed Resolution
A property of a test system which enables the separation of signals due to defects in.the test specimen that
are located in close proximity to each other.
Diamagnetic
A material having a permeability less than that of a vacuum.
Differential Coil
A test arrangement which tests the specimen by comparing the portion being tested with either another
portion of the same specimen or to a known reference specimen.
Discontinuitv, Artificial
Reference discontinuities, such as holes, grooves, or notches, which
are introduced into a reference
standard to provide accurately reproducible sensitivity levels for electromagnetic test equipment.
Double Coil
A test arrangement where the alternating current is supplied through one coil while the change in material
condition is measured
from a second coil.
Eddy Current
L
A circulating electrical current induced in a conductive material by an alternating magnetic field.
Inspector's Handbook

Edge or End Effect
The disturbance of the magnetic field and eddy currents due to the proximity of an abrupt change in
geometry (edge, end). The effect generally results in the masking of discontinuities within the affected region.
f
Effective Depth of Penetration d
The depth in a material beyond which a test system can no longer detect a change in material properties.
Effective Permeability
A hypothetical quantity
conductor in an encircling coil.
which is used to describe the magnetic field distribution within a cylindrical
The field strength of the applied magnetic field is assumed to be uniform over the
entire cross section of the test specimen
with the effective permeability, which is characterized by the conductivity
and diameter of the test specimen and test frequency, assuming values between zero and one, such that its
associated amplitude is always less
than one within the specimen.
Electromagnetic Induction
The process by which
a varying or alternating current (eddy current) is induced into an electrically
conductive test object by a varying electromagnetic field.
Electromagnetic
Testing
That nondestructive test method for engineering materials, including magnetic materials, which uses
electromagnetic energy having frequencies less than those of visible light to yield information regarding the quality
of the tested material.
Encircling Coil
A coil, coils, or coil assembly that surrounds the part to be tested. Coils of this type are also referred to as
circumferential, OD or feed-through coils.
w
External Reference Differential
A differential test arrangement that compares a portion of the test specimen to a known reference standard.
Ferromagnetic
A material which, in general, exhibits hysteresis phenomena, and whose permeability is dependent on the
magnetizing force.
Fill Factor
For
an inside coil, it is the ratio of the outside diameter of the coil squared to the inside diameter of the
specimen squared. For an encircling coil, it is the ratio of the outside diameter of the specimen squared to the
inside diameter of the coil squared.
Flux Density
A measure of the strength of a magnetic field expressed as a number of flux lines passing through a given
area.
Henry
The unit of inductance. More precisely, a circuit in which an electromotive force of one volt is induced
when the current is changing at
a rate of one ampere per second will have an inductance of one henry. (Symbol: H)
Hertz
The unit of frequency (one cycle per second). (Symbol:
Hz)

High Pass Filter
An electronic circuit designed to block signals of low frequency while passing high frequency signals.
IACS
k The International Annealed Copper Standard. A value of conductivity established as a standard against
w
which other conductivity values are referred to in percent IACS.
Impedance
The ovtmsition to current flow in a test circuit or a coil due to the resistance of that circuit or coil, plus the
electrical of the coil as affected by the coil's magnetic field.
Impedance Analysis
An analytical method which consists of correlating changes in the amplitude, phase, or quadrature
components (or all of these) of a complex test signal voltage to the electromagnetic conditions
within the
specimen.
Impedance-plane Diagram
A graphical representation of the locus of points indicating the variations in the impedance of a test coil as
a function of basic test parameters.
Inductance
The inertial element of the electric circuit.
An inductor resists any sudden change in the current flowing
through it.
Inductive Reactance
The opposition to current flow in a test circuit or coil when
an alternating voltage source is applied and due
solely to the electrical properties of the
mil as affected by the magnetic field.
b
Inertia
The property of matter which manifests itself as a resistance to
any change in the momentum of a body.
Lift-off
The distance between a
swface probe coil and the specimen.
Lift-off
Effect
The
effed observed due to a change in magnetic coupling between a test specimen and a probe coil
whenever the distance between
them is varied.
Low Pass Filter
An electronic circuit designed to block signals of high
frequency while passing low frequency signals.
Magnetic Field
A condition of space near a magnet or current-carrying wire in which forces can be detected.
Magnetic
Flux Lines
A closed curve in a magnetic field through points having equal magnetic force and direction.
Noise
Any undesired signal that tends to interfere with the normal reception or processing of a desired signal.. In
haw detection, undesired response to dimensional and physical variables (other
than flaws) in the test part is called
"part noise.
Inspector's Handbook
6- 3

Nonferroma.gnetic
A material that is not magnetizable and hence, essentially not affected by magnetic fields. This would
include paramagnetic materials having a magnetic permeability slightly greater than that of a vacuum and
approximately independent bf the magnetizing force
and diamagnetic materials having a permeability less tha-
''
of a vacuum. V
Paramagnetic
A material having a permeability which is slightly greater than that of a vacuum, and which is
approximately independent of
the magnetizing force.
Permeability
A measure of the ease with which the magnetic domains of a material align themselves with an externally
applied magnetic field.
Permeability Variations
Magnetic inhomogeneities of a material.
Phase Analysis
An instrumentation technique which discriminates between variables in the test part by the different phase
angle changes which these conditions produce
in the test signal.
Phase Angle
The angle measured degrees that the current in the test circuit leads or lags the voltage. One complete
cycle is equal to
360".
Phase
Shift
A change in the phase relationship between two alternating quantities of the same frequency. w
Probe Coil
Asmall coil or coil assembly normally used for surface inspections.
- Reference Standard
A test specimen used as a basis for calibrating test equipment or as a comparison when evaluating test
results.
Reiection Level
The setting
of the signal level above or below which all parts are rejectable or in an automatic system at
which objectional parts will actuate the reject mechanism of the system.
Resistance
The opposition to current flow in
a test circuit or coil based on specific material properties and cross-
sectional area and length of a conductor.
Response Amplitude
The property of the test system whereby the amplitude of the detected signal is measured without regard to
phase.
Saturation
The degree of magnetization produced in
a ferromagnetic material for which the incremental
permeabili
has decreased substantially to unity.
Inspector's Handbook

Self-comparison Differential
A differential test arrangement that compares two portions of the same test specimen.
Signal- to-noise Ratio
L
The ratio of response or amplitude of signals of interest to the response or amplitude of signals containing
no usell information.
Single Coil
A test arrangement where the alternating current is supplied through the same coil
from which the
-
indication is taken.
Skin Effect
A phenomenon where, at high frequencies, the eddy current flow is restricted to a thin layer of the test
specimen close to the coil.
Standard
A reference used as a basis for comparison or calibration; a concept that has been established by authority,
custom, or agreement to
serve as a model or de in the measurement of &tity or the establishment of a practice
or a procedure.
Standard Depth of Penetration
The depth
in a test specimen where the magnitude of eddy current flow is equal to 37 percent of the eddy
current flow at the surface.
Inspector's Handbook
6-5

Two Types of Electrical Current
Direct Current (DC)
4
- Current flow is constant over time
- Current is distributed uniformly over the cross-section of the conductor
- Example: battery
Current strength and direction remain constant over time
Time
Alternating Current
(AC)
- Current flow varies over time
w
- Current flows at or near the surface of the conductor - this phenomenon is called the SL,
effect
- Example: 60 cycle ac in wall sockets
Current strength varies over
time; current
direction reverses every
112 cycle
Time
Inspector's Handbook'

Conductivity and the IACS
Conductivity of a metal is usually expressed as a percentage (%) and is based on the international annealed copper
standard (IACS).
k.
A specific grade of high purity copper was designated as 100 % conductivity. All other metals (except silver) are
designated some
% less then 100 %. These percentages indicate the relative efficiencies of the various metals for
carrying electric current.
Right Hand Rule
L
An easy method for fmding the direction of an electrically induced magnetic field is to imagine grasping the
conductor in the right hand with the thumb pointing in the direction of the current flow. The fingers will
then point
in the direction of the lines of force. This is the right hand rule and is shown below. From this
figure it can be seen
that the current flow in the conductor creates circular
lines of force.
CURRENT
FLOW
The coil's magnetic field intensity (strength) decreases with'in~reasin~ distance away from the outside of the coil.
C*
The field intensity at point C is less
than at point B, and point B's intensity
C is less than point A's
B
A
Inspector's Handbook

C1
The coil's field intensity (strength) is assumed to be constant across the inside
diameter of the coil. This assumption is based on the use of AC and small
diameter coils, and for all practical purposes the assumption is valid.
W'
' \./-
Y
Lines of
Force
The coil's magnetic field can
be viewed as a distribution of lines of
force
around the coil. These lines of force are call magnetic flux,
and
represent the coil's magnetic force (symbol 'H').
Current Current
in
-0-
out
C.--
-
0
I
When a metal rod is placed inside the coil, the coil flux passes through the
rod. The number of lines of force in the rod divided by the cross-sectional 'N
area of the rod equals the flux density (symbol 'B') in the rod. The flux
density in the rod depends on the metal's willingness to cany the magnetic , '
flux. The metal's willingness to carry these magnetic flux lines is called /
permeability. The symbol for permeability is 'p' (mu).

'
N-* ---I- w
Mathematically, permeability is expressed as the flux density in the material (B) divided by the magnetizing force
(H) that caused it.
Permeability
B
=
orp
H
Flux densih
Magnetizing force
Like conductivity, permeability is a material property that is the same for all samples of a particular material
(assume same chemistry, etc.).
example: p, for air = 1
p for copper alloys = 1
p, for steels = several thousand

The permeability value of 1 for air and copper alloys (and all other nonmagnetic materials) means that the
magnetic
flux in the material is exactly equal to the flux coming from the coil.
b
stated another way: b/h = 1 only when b = h
The
high permeability value of steels (and all other ferromagnetic metals) means that the magnetic flux in the
metal is thousands of times greater
than the applied flux fiom the coil.
stated another way:
b/h = 2000 means h,, = 2000 x h,,
Magnetic Domains
Obviously, something is happening in the ferromagnetic metals to create all this additional flux that is not
happening in the nonmagnetic materials. Magnetic domains are groups of atoms within a ferromagnetic metal
which behave like
tiny permanent magnets.
In
unmagnetized magnetic materials, the domains are randomly oriented
and neutralize each other, producing no observable magnetic
flux in the
. metal.
w
When the magnetizing force fiom the coil, is applied, the domains begin
to align in the direction of the applied flux. Their combined individual
magnetism starts to produce an observable increase in the
flux in the
metal, over and above the applied
flux (H).
When the domains are completely aligned, the metal is said to be
saturated, and the flux 'B' is many thousands of times greater than the
applied
flux
'HI. This domain behavior is responsible for the mrrlinear
relationship between (E3) and (H) in ferromagnetic metals and for the
hysteresis effect.
Partially Oriented Domains
Inspector's Handbook
Completely Oriented
Domains (saturation)

When a coil of wire carrying alternating current is brought into proximity to a conducting article. The alternating
magnetic field that surrounds the coil will penetrate the article, generating small circulating electrical currents,
called eddy currents, in an article.
Note: When a generator's
electrical current reverses it
direction, the direction of the
eddy currents will ako reverse. II II
Electrical current
$4
Test coil
Article being tested
Eddy currents
are circulating electrical currents induced in an isolated conductor by an alternating
magnetic field.
Note that there is no direct electrical contact between the coil and the test article
- eddy currents are generated by
electromagnetic induction.
Direction of coil's field
The
"primary" magnetic field
surrounding the ac coil will penetrate
the test articles and induce eddy
cmts in the article. The circulating
Ac
eddy currents possess their own
"secondary" magnetic field.
This
secondary field will oppose the coils .
1. I
and reduce the size and strength of the \I ,# --*
coil's field.
A
Eddy current field
opposes coil's field
Inspector's IFanhk

Changes in the strength or shape of the secondary field will affect the primary field, which will affect the AC
flowing in the coil, where it will be sensed.
LTn this way, variations of the test article that disturb or alter the flow of the eddy currents will disturb the
electromagnetic coupling between the two fields and cause indications on the test instnunent
Characteristics of Eddy Current
1) Can only be induced in conductors
Test circuit
Changes in
conductivity
Coated (i.e. painted)
articles may
be tested, since the
coils field will pass through the
nonconducting coating and
&@) onc conductive material

generate eddy currents in the metal
\e
-
Change in coil's
impedance
-------------.----I--------------------.
Change in coil's
magnetic field
beneath.
Change
in
meter reading
Plated articles should not
be
tested, since the coil's field will
generate eddy currents in both the
metallic plating and the base
material. Consequently,
ET
indications could originate
from
either the base metal or the
plating, confusing the inspection.
Material
1--conductive material
*Conductive material
-Conductive mate
2) Can be generated only by an alternating magnetic field - there must be relative motion between the field and
the test article. A
DC field will not generate eddy currents. The moving AC field which builds up, then breaks
down and reverses direction every 112 cycle, is essential to the production of eddy currents.
3) Eddy currents flow
in circular paths,
parallel to the coil
windings.
/ENCIRCLING COIL
CRACK
EDDY
CURRENTS

Depth of Penetration
Eddy currents are strongest at the surface nearest the coil (due to skin effect) and weaken with depth. The depth of
eddy current penetration below the surface is directly affkcted by the nearness of the coil to the test article, the
operating frequency, and the test article conductivity and permeability.
I4
(A) Coil position - since the coil's field is limited in size and decreases in strength with increasing distance away
from the coil,
maximum field penetration into the article and, therefore, maximum depth of eddy current
penetration is achieved by
mving the coil as close as practical to the test article surface.
02, /='
I I
1 + '8
coil far away 71
from article 1 I -
being tested
possible to the
article being
tested
(B) Operating frequency - a relationship also exists between the frequency of the ac applies to the test coil and the
eddy current depth of penetration.
As the frequency is increased, eddy current distribution concentrates near
the surface and decreases deep with the test article. The reverse is also true. As the frequency is lowered, the
eddy current distribution extends deeper into the article.
Depth of
Penetration
I I
View A
Frequency
-
Depth of
Eddy Current
Penetration
View
B
In both view A and B above, the material and the test coil are the same. Since view a shows deeper eddy current
penetration into the material, this means that a lower frequency was used. View
B shows shallower penetration, so
a
high frequency was used. Keep in mind that a high frequency causes the eddy currents to accumulate near the
surface closest to the test coil.

c) Conductivity - the figure below illustrates that the depth of eddy current penetration also varies with metal's
electrical conductivity. As conductivity increases, the depth of eddy currents decreases.
In the figure, the coil and test frequency are the same in each view.
Only the
material type is different. You can
verifl that tin is more conductive the lead, and that copper is much more conductive than either, by referring to the
% IACS conductivity chart shown earlier. As the figure shows, the less conductive metals achieve deeper eddy
current penetration
than the more conductive metals.
'c/
Indicator Indicator Indicator
oil Coil oil
d) Magnetic permeability
-
fdy, a metal's magnetic permeability (p) affects the depth of eddy current
penetration. The depth of penetration decrease as the permeability increases. There are
3 basic types of eddy
current test: surface
, encircling , and inside.
A surface coil is designed to
be used on localized areas on a surface, and is usually contained in a hand-held probe.
'L
Depth of
Eddy
Current
Penetration
An encircling coil, on the other hand, is large enough to surround an object about one of its axes and is designed to
test an
entire segment of the object at one time.
2
.'.::..::.'.:::.:;:.:
:..::-.:::.::.::.
. . ..... .. ..
:. :::.,::::: :.:
Depth of -
Eddy
Current
Penetration
Inspector's Handbook
Lead Tin copper

Encircling Coil
An inside coil is designed to be placed inside a hole or cavity in the object, and is especially suited for testing thin
wall tubing.
ARTICLE
bb$Lc
--,co,L
INSIDE COIL
Note that with each of the coil types:
- The eddy currents circulate parallel to the coil windings
- The eddy currents hug the surface that is nearest the coil

Each of these 3 coil types may be used in either the differential or absolute test mode.
In the differential coil arrangement, two side-by-side coils are wound and connected so that the output of on
cancels the output of the other
as long as the test object properties are the same under both coils. This mode is most ensitive to small defects and is relatively insensitive to material variations such as hardness, gross surface
megularities, etc.
P1
DIFFEREN TlAL
In the absolute mode, a single coil tests the area of the test object beneath it without comparison to a reference
area This mode is most sensitive to large defects longer than the coil, and to material variations such as hardness,
gross surface irregularities, etc.
ABSOLUTE COIL
The 3 general material variables (properties) that affect the flow of eddy currents in the material are:
1) Changes in conductivity - conductivity changes may be caused by variations in alloy chemistry or heat
treatment, or may
be due to the presence of defects. Since cracks or other discontinuities force the eddy
currents to take a longer path by flowing around them, the overall effect of the discontinuity is to reduce the
conductivity of the metal.
TEST COI L
EDDY CURRENT MAGNETIC FIELD
MAGNETIC FIELD ,TEST COIL
EDDY CURRENT MAGNETIC FIELD
CRACK
EDDY CURRENT

As the figure illustrates, the eddy currents must flow around the crack, effectively reducing the conductivity of the
metal.
2) The second material variable affecting eddy current flow is magnetic permeability. Eddy currents are
induf '
by flux changes in the metal and are directly related to the density or amount of flux. Since changes in
'4
permeability cause changes in the amount of flux in the metal, they also cause a pronounced (and detectable)
change
in the eddy current flow.
3) Changes in the physical
dimensions, or size and shape of the test object also affect the eddy current flow.
Although the figure below is a gross example, it clearly illustrates how a change
in physical dimension can
alter the electromagnetic coupling between the coil and the object.
Two more dimensional of eddy current testing is edge effect and lift-off.
Edge
effed is the false indication caused by disruption of by disruption of the eddy current path when the coil
approaches an end or edge of the material.
w
The effect is strong enough to "mask' any changes due to other factors. In effect, the edge of the material looks he
a very large crack to the eddy current instrument.
On the other hand, the false indication caused by changing the spacing between the test coil and the material
dace is called lift-off.
-------------'
MAGNETIC
Inspector's Handbook

Lift-off has a very large effect on the ET output display due to the decrease in primary field flux in the material as
the coil distance from the materials surface is increased.
The lift-off effect can
be used to measure the thickness of nonconducting coatings, such as paint, on a conducting
object.
WONCONDUC
SURFACE
I
1
CvnOUCTlVE MATERIAL
I I
ARTICLE
b
Ace eddy currents cannot be generated in the nonconductor, a coil placed in contact with the painted surface
"sees" the paint thickness simply
as lift-off distance.
Another important relationship between eddy current flow
and the presence of discontinuities is that the
discontinuity must lie perpendicular to the direction of eddy current flow to
be detected.
INSPECTION COIL
EDDY CURRENTS
' SURFACE CRACK
SUBSURFACE
LAMINAR SEPARATION
In the situation above, a surface coil passes over a surface crack and a subsurface lamination in the metal. It is easy
to see that the crack will force the eddy currents to take a longer path around it, causing a detectable disruption
in - their flow. The lamination on the other hand, will not cause much disruption of the eddy current path since the
. netal separation lies parallel to the direction of current flow.
Inspector's Handbook
6-17

Limitations of Eddy Current Testing
1. Inspect only conducting articles (i.e. metals).
2. Can locate only dace and shallow subsurface discontinuities; inspection depth is limited to less then 1 ii.
3. Separation of the effects of conductivity, permeability, and dimension variables is difficult and often not
possible.
4. ET is an indirect inspection requiring the use of calibration standards; you must know what you are looking for
in order to find it.
Advantages of Eddy
Current Testing
1. Able to inspect through nonconductive coatings (i.e. paint).
2. Fast, real-time inspection.
3. Totally nondestructive; no interference with the test item.
Summary of Properties of Eddy Currents
1. Generated by an alternating magnetic field.
2. Flow only in conductors.
4
3. Circulates parallel to coil windings.
4. Eddy current flow is affected by changes in the material's conductivity, dimension, magnetic permeability.
5. Limited to surface/shallow subdace testing.
6. Depth of penetration is affected by conductivity and permeability of test object, by test frequency, and by
nearness of the coil to the test object.
7. Able to test through surface coatings (nonconducting) but not through plating (metal).
Eddy Current Relationship of Properties
Inspector's Handbook
Penetration
Decrease
Increase
Frequency
Increase
Decrease
Conductivity
Increase
Decrease
Permeability
Increase
Decrease

Chapter 7 - Radiographic Inspection
Common Definitions and Examples
w Absorbed dose
The amount of energy imparted to matter by an ionizing particle
per unit mass of irradiated material at the
place of interest.
It is expressed in
"'rads."
Accelerator
A device that accelerates charged atomic particles to high energies. An x-ray machine is an accelerator.
Activity
A measure of how radioactive a particular radioisotope is. The number of atoms decaying per unit of time
calculates activation. Its unit of measurement is the "curie."
Alpha particle
A positively
charged particle emitted by certain radioactive materials. It is made up of two neutrons and
two protons; hence it is identical
with the nucleus of a helium atom.
Alpha ray
A stream of fast-moving helium nuclei (alpha particles). This radiation is strongly ionizing with very weak
penetration.
An~strom
A unit of length used to express wavelength. One angstrom equals lo-* centimeters.
-Q. We (target side)
The positive terminal of an x-ray tube. It is a high melting point element that receives the electron
bombardment from the cathode (filament).
Atom
The smallest part of an element. The atom consists of
a nucleus composed, with the exception of hydrogen,
of a number of protons and neutrons. Included in the atom is an extranuclear portion composed of electrons equal
in number to the protons in the nucleus. The hydrogen atom includes a nucleus of one proton and extranuclear
portion of one electron.
Autotransformer
A special type of transformer in which the output voltage can be easily varied. The autotransformer is
employed to adjust the primary voltage applied to the step-up transformer that produces the high voltage applied to
the
x-ray tube.
Background radiation
The radiation of man's radiation natural environment, consisting of radiation that comes
from cosmic rays
and from the naturally radioactive elements of the earth, including radiation from within man's body. The term
may also mean radiation extraneous to an experiment.
Backscatter
Radiation scattered hm the floor, walls, equipment, and other items in the area of a radiation source.
Sackscatter includes secondary radiation resulting from the interaction between the primary radiation from the
, ' source and the material being radiated.
Inspector's Handbook

Beta particle
An electron or position emitted from a nucleus during radioactive decay.
Bremsstrahlung
~lectroka~netic radiation (photon) emitted by charged particles when they are slowed down by eled L-
fields in their passage through matter. Literally means, "braking radiation" in German.
200 Kev Electron Leaving
400 Kev Electron 8
200 Kev X-Ray
A lightproof container, which may or may not contain intensifying
andlor filter screens, that is used for
holding the radiographic
films in position during the radiographic exposure.
Cathode (filament side)
The negatively-biased electrode of the x-ray
tube.
's/
A device used to surround a radiation source and so constructed as to both minimize the scattered radiation
and to direct the primary or useful radiation into a more or less parallel beam onto a localized area.
Compton Effect
The glancing collision of an x-ray or gamma ray
with an electron to an orbital electron in matter with a
lower
enxgy in matter with a lower energy photon scattered at an angle to the original photon path. The electron
does not absorb all of the energy.
High energy
Photon de-.
0e
Ejected electron
/
/ Photon
/@-o-.
1
continues with
4 -
e'L-- '
less energy
'I

I.
Inspector's Handbook

Contrast (film)
The change in density recorded on the film that results from a given change in radiation input. Contrast is
determined hthe slope of the characteristic curve.
Tontrast (radiographic)
L
The measure of difference in the film blackening resulting from various x-ray intensities transmitted
through the object and recorded as density differences in the image. Thus, difference in
film blackening
from one
area to another is contrast.
Contrast (subiect]
The ratio of radiation intensities passing through selected portions of a specimen.
Definition
The measure of sharpness in the outline of the image of
an object recorded on film, the sharpness is the
function of the types of screens, exposure geometry, radiation energy and film characteristic.
Densitometer
An instrument utilizing the photoelectric principle to determine the degree of darkening of developed
photographic
film.
Developer
A chemical solution that reduces exposed silver halide crystals to metallic silver.
Dose
-
The amount of ionizing radiation energy absorbed per unit mass of irradiated material at a specific location,
such as a part of the
human body.
'Y Dose rate
The radiation dose delivered
per unit time and measured, for instance, in
rems per hour.
Dosimeter
A device that measures radiation dose, such as a film badge or ionization chamber.
Duty cvcle
Usually expressed in a percentage to represent the time used versus the time not used. Electromametic Spectrum
Represents the electromagnetic waves of different wave lengths. The lines are not definie boundaries but
rather phase into one another.
DECREASING - WAVELENGTH - INCREASING
INCREASING - FREQUENCY - DECREASING
X-RAYS
AND
GAMMA
RAYS
L INCREASING - ENERGY - DECREASING
Inspector's Handbook
7-3
ULTRAVIOLET
RAYS
LIGHT
RAYS
INFRARED
RAYS RADAR
SHORT
WAVE
RADIO
LONG
WAVE RADIO

Electron volt
Is an amount of energy equal to the energy gained by one electron when it is accelerated by one volt.
Emulsion
A gelatin and silver bromide crystal mixture coated onto a transparent film base.
Encapsulation
The process of sealing radioactive materials to prevent contamination.
Filament
A piece of wire in the cathode side, negative side, of the x-ray tube used to produce electrons when heated.
Specialized
film used for radiographic purposes. The components of the film are two protective layers, two
emulsion layers, and one acetate base layer.
acetate protective
,........... ............
base t layers
Film bad~e
A package of photographic film worn as a badge by workers in the nuclear industry to measure exposure to
ionization radiation. The absorbed dose
can be calculated by the degree of film darkening caused by the irradiation.
Filter
A layer of absorptive material that is placed in the beam of radiation for the purpose of absorbing rays,
.d
certain wavelengths and thus controlling the quality of the radiograph.
Fixer -
A chemical solution that dissolves unexposed silver halide crystals from developed film emulsions.
Fon
A darkening of the film resulting from chemical action of the developer, aging, scattered or secondary
radiation, pre-exposure to radiation, or exposure to visible light.
Geiger counter
A radiation detection and measuring instrument. It contains a gas- filled tube that discharges electrically
when ionizing radiation passes through it. Discharges are counted to measure the radiation's intensity.
Graininess
A film characteristic that consists of the grouping or clumping together of the countless small silver grains
into relatively large masses visible to the naked eye or with slight magnification.
Half- life
The time in which half the atoms in a radioactive substance decay. Time is dependant upon the element.
Half- life (biological)
The time required for a biological system, such as a man or
an animal, to eliminate, by natural
processr _c
half the amount of a substance that has entered it.
7-4 Inspector's Handbook

Hal6 value layer
The thickness of a material required to absorb one half of the impinging radiation.
F
Intensifying screen
A layer of material placed in contact with the film to increase the effect of the radiation, thereby shortening
'v
he exposure.
Interlock
A device for precluding access to an area of radiation hazard either by preventing entry or by automatically
removing the hazard.
Ion
-
A charged atom or molecularly-bound group of atoms; sometimes also a free electron or other charged
subatomic particles.
Ion
pairs
A positive ion and a negative ion, or electron, having charges of the same magnitude and formed from a
neutral atom or molecule by the action of radiation or by any other agency that supplies energy.
Ionization
The process of adding electrons to, or knocking electrons from, atoms or molecules thereby creating ions.
High
tempe~tures, ele~tricaldischar~es, and nuclear radiation can cause ionization.
Ionization chamber
An instrument that detects and measures ionizing radiation by observing the electrical current created when
radiation ionizes gas in the chamber making the gas a conductor of electricity.
,onizing radiation
Any radiation that directly or indirectly displaces electrons from the orbital shells of atoms.
&v
The energy of X-rays or gamma rays measured in thousand electron volts.
Latent image
The potential image that is stored in the form of chemical changes in the film emulsion and is brought out
by development of the
film.
Latitude
Latitude most closely aligned with contrast is commonly called the scale of the
film. Latitude is the range
of thickness of material
that canbe transferred or recorded on the radiograph within the usell reading range of
film density. A high contrast film has little latitude and conversely a low contrast film has great latitude.
Leak test
A test on sealed sources to assure that radioactive material is not being released.
Licensed material
Source material, special nuclear material, or by-product material received, possessed, used, or transferred
under a general or speciailicense issued by the Nuclear Regulatory Commission.
Inspector's Handbook
7-5

Mev -
The energy of X-rays or gamma rays measured in million electron volts.
Microshrinkage
Cracks that appear as dark feathery streaks, or irregular patches, that indicate cavities in the grain
w
boundaries.
Monochromatic radiation
A rare condition, hypothetical, in which all gamma rays
oi x-rays produced are of the same wavelength.
Pair production
The transformation of a high-energy ray into pair of particles (an electron and a positron) during its passage
through matter.
Particle
A minute constituent of matter with a measurable mass, such as a neutron, proton, or meson.
Penetrameter
A small strip of material of the same
composition
as the specimen being tested. Its thickness
T = thickness 4TDIA T DIA 2T DIA
Ik I
represents a percentage of the specimen thickness. I
When placed in the path of the rays, its image on the
radiograph provides a check on the radiographic technique
employed.
Penumbra
The shadow cast when the incident radiation is partly, but not wholly, cut off
by an intervening body; t
-
space of partial illumination between the umbra, or perfect shadow, on all sides and the fidl light.
Photoelectric effect
This process involves the complete absorption of the photon during the process of knocking
an electron out
of orbit. It occurs primarily
with lower energy X-rays photons of 10 Kev to 500 Kev.
Approaching Photon
....a
/e Ejected electron
(negative ion)
Photon absorbed
0 @
/
4-.
/

/ g4-' . '
/
\'
I

'

'.-- 0

,'
/ ' Charged atom
--e4 ' (positive atom)
Photon 4
A discrete quantity of electromagnetic energy. Photons have no momentum but no mass or electrical
charge.
7-6 Inspector's Handbook

Positron
A hdamental atomic particle having a mass equal to that of the electron and possessing a positive charge
equal to the negative charge of the electron.
<
'VRoentaen
A unit of exposure dose of ionizing radiation. It is that amount of gamma or x-rays required to produce ions
carrying
1
electmst&ic unit of electrical charge in one cubic centimeter of dry air under standard conditions.
Safelight
A special lamp used in the darkroom to provide working visibility without affecting the photosensitive
emulsion of the radiographic
film.
Scatter
Secondary radiation that is emitted in all directions.
Screens
Metallic or fluorescent sheets used to intensify the radiation effects on films.
Sensitivity
A term usually referring to the ability of the radiographic procedure to detect discontinuities.
Specific activity
Total radioactivity of a given isotope
per gram of element.
Source- film-distance
The distance between the focal spot of an x-ray
tube or radiation source and the film, generally expressed
.n inches.
Tar~et
The piece of material, usually tungsten, embedded in the anode side, positive side, of the x-ray tube. A
effective and efficient target has the following four properties high atomic number, high melting point, high
thermal conductivity, and low vapor pressure.
Two-
film technique
A procedure wherein two films of different relative speeds are used simultaneously to radiograph both the
thick
and the thin sections of an item.
Inspector's Handbook

Structure of the Atom and an Element
$ Proton - A heavy atomic particle with a positive charge.
0 Neutron - Close to the same weight and size of the proton with a neutral charge.
Electron
- A negative charged particle weighing about
111840'~ of a proton or a neutron.
Nucleus
- The
proton(s) and ~utron(s) are group here in the center of the atom.
Atomic number "Z" - This number represents the number of protons in the atom.
Mass number
"A" - This number represent the number of protons and neutrons in the atom.
fi Helium Atom
E = element symbol
Z = atomic number
A = mass number
Components of an Isotope
Isotope - One or more of the same element having the same number of protons but not the same number of
neutrons.
Natural isotopes
- Those that occur naturally.
v/
Artificial isotope - Those elements that are created by bombarding with swarms of neutrons.
Activation
- This is the process of creating artificial isotopes.
Stable isotopes
- Atoms that are not radioactive.
Unstable isotopes
- Atoms that are radioactive.
Characteristics of A Radioactive Element
During the decay or disintegration process tiny particles of energy are emitted in the form of particles and
waves
hm the nucleus.
Alpha particles (a)
- The biggest and heaviest of the radiation particles and is composed of two protons and two
neutrons.
Beta particles
(13) - A very light particle, actually a high-speed electron.
Gamma rays (?) - A form of energy that is a wave not a particle.
Two Types of Radiation
Gamma radiation - A product of nuclear disintegration or decay of radioactive elements.
X-rays
- An artificial produced wave
from a high voltage electron tube.
1) Soft x-rays
- low energy.
2) Hard x-rays - high energy.
Inspector's
Handbook

History of Radiography
X-rays were discovered in 1895 by Wilhelm Conrad Roentgen (1 845- 1923)
who was a Professor at Wuerzbug University in Germany. Working with a cathode- - -ay tube in his laboratory, Roentgen observed a fluorescent glow of crystals on a
table near his
tube. The tube that Roentgen was working with consisted of a glass
envelope (bulb) with electrically positive and negative electrodes encapsulated in it.
The
tube was evacuated of air, and when a high voltage was applied to it, the tube
would produce a fluorescent glow. Roentgen shielded the tube with heavy black
paper, and found that a green colored fluorescent light could be seen
from a screen
setting a few feet away from the tube. He concluded that a new
type of ray emitted
from the tube. This ray was capable of passing through the heavy paper covering. He
also found that the new ray would pass through most substances casting shadows of
solid objects.
In his discovery, Roentgen found that the ray would pass through the
tissue of humans leaving the bones and metals visible. One of Roentgen's
first
experiments late in 1895 was a film of his wife, Bertha's hand with a ring on.
However, it can
be argued that the
fkst use of X-rays was for an industrial (not
medical) application as Roentgen produced a radiograph of a set of weights in a box to show his colleagues.
Roentgen's discovery was a scientific bombshell, and was received with
extraordinary interest by both scientist and laymen. Scientists everywhere could
,duplicate his experiment because the cathode tube was very well known during this
period. Many scientist dropped other lines of research to pursue the mysterious rays,
and the newspapers and magazines of the
day provided the public with numerous
stories, some true, others fanciful, about the properties of the newly discovered rays.
The public fancy was caught by the invisible ray with the ability to pass through solid
matter,
and, in conjunction with a photographic plate, provide a picture, albeit a
shadowy diffuse one, of the bones and interior of the body. Scientific fancy was
captured by an extraordinary new radiation, of shorter wavelength than light, that
presaged new and great vistas in physics, and the structure of matter. Both the
scientist and the public were enthusiastic about potential applications of the newly
discovered rays as an aid in medicine and surgery.
Thus, within a month after the
announcement of the discovery, several medical radiographs had been made
& Europe and the United States that
were used by surgeons to guide
them in their work. In June 1896, only 6 months
after Roentgen announced his
discovery, X-rays were being used by battlefield physicians to
- -
locate bullets in wounded soldiers.
Prior to 1912, X-rays were used little outside the realms
of medicine, and dentistry, though some X-ray pictures of metals
were produced. The main reason that were not used in industrial
application before this date was because the X-ray tubes (the
source of the X-rays) of that period broke down under the
voltages required to produce rays of satisfactory penetrating
power for industrial purpose. However, that changed in 19 13
when the high vacuum X-ray tubes designed by Coolidge
became available. The high vacuum tubes were an intense and
reliable X-ray sources, operating at energies up to 100,000 volts.
In 1922, industrial radiography took another step
forward with the advent of the 200,000-volt X-ray tube that
allowd radiographs of three inches thick steel parts to
be produced
in a reasonable amount of time. In 1931, General Electric Company developed 1000,000 volt X-ray L/ qenerators. That same year, the American Society of Mechanical Engineers (ASME) permitted X-ray approval of
fusion welded pressure vessels.
Inspector's Handbook 7-9

gatherin
types of
:--.--+: -
certain I
fluoresc
Shortly after the discovery of X-rays, another form of penetrating rays was discovered. In 1896, French
scientist Henri Becquerel discovered radioactivity somewhat by accident, like many other great scientific
discoveries. Many of the scientists of the period were working with cathode
rays, and other scientists were ~g evidence on the theory that the atom could be subdivided. Some of this new evidence showed that cer'qi-
/
' atoms disintegrate by the rnselves. It was Henri Becquerel who discovered this phenomenon while d
ulvcar~~ating the properties of fluorescent minerals. Becquerel was working on the principles of fluorescence,
minerals glow (fluoresce) when exposed to sunlight. He utilized photographic plates to record this
:ence.
I
expose
-
A
questior
the fog
- - - . - -. . .
led whal
*g was
. - - . .. .
One of the minerals Becquerel worked with was a uranium compound. On a day when it was too cloudy to
his samples to direct sunlight, Becquerel stored some of the compound
in a drawer with photographic dates. When he developed these plates a couple of days later, he discovered that they were fogged. Becquerel
t would have caused this fogging. He knew he had wrapped the plates tightly before using them, so
-
not due to stray light. In addition, he noticed that only the plates that were in the drawer with the
umuum compound were fogged. Becquerel concluded that the uranium compound gave off a type of radiation that
could penetrate heavy paper and affect photographic
film. Becquerel continued to test many samples of uranium
compounds and determined that the source of radiation was the element uranium. At this time, enough information
was gathered to determine that an element, which gives off radiation, is said to
be radioactive, and possesses the
property of radioactivity. Becquerel's discovery was, unlike that of the X-rays, virtually
unnoted by the layman and
scientist alike. Only a relatively few scientist were interested
in Becquerel's findings, and it was not until the
discovery of radium by the Curies two years later that interest in radioactivity became wide spread.
While working in France at the time of Becquerel's discovery, Polish scientist Marie Curie became very
interested in his work. She too, suspected that a
uranium ore known as pitchblende contained other radioactive
elements. Marie and her husband, a French scientist, Pierre Curie started
looking for these other elements. In 1898,
the Curies discovered another radioactive element in pitchblende; they named it 'polonium' in honor of Marie
Curie's native homeland. Later that same year, the Curie's discovered another radioactive element for which
the*-
named 'radium', or shining element. Both polonium and
radium are more radioactive than uranium. Since thes~ -
discoveries, many other radioactive elements have been discovered or produced.
The initial gamma ray source was
radium, which allows radiography of castings up to 10 to 12 inches thick
During World War
11, industrial radiography grew tremendously as part of the Navy's shipbuilding program.
Shortly after the war, manmade gamma ray sources such as cobalt and iridium became available in 1946. These
new sources were far stronger
than radium sources and were less expensive. Thus the
manmade sources rapidly
replaced radium, and the use of gamma rays grew quickly in industrial radiography.
7-10 Inspector's Handbook

60" Coverage for Pipes and Location Marker Measurements
I General Information I Distance Between Location Markers (centerline) 1
Outside Circumference
k.4.
I
Outside Circumference 60"
L~ NPS Diameter (OD times pi) Coverage
Inspector's Handbook 7-11
12 5 I1 7 9 6 8 10

Common Math Formulas
Ii(D1) = 12(D2) 2
Ma, (SFD , )2
-
Ma, -
(SFD 1
2
2
Ma, (SFD 2)2
-
Ma -
(SFD )
1
Ma=Milliamperage SFD=Source to film distance
J",:'" ,"
SFD , ,=
a, (SFD 1)2
a, =
2
(SFD )
SFD ,
a , (SFD )
a2
(SFD )
1
Ci=Curie SFD=Source to film distance
Inspector's Handbook

2
Ef, (SFD ,
Ef, =
2
(SFD )
Ef (SFD 2)'
Ef, =
(SFD )
Ef=Exposure factor SFD=Source to film distance
SFD ;i' T2 (SFD 1)2
1
-
T1 (SFD 2)2
SFD
T2 -
(SFD )
1
T=Time SFD=Source to film distance
OF, (SFD
)
OF, =
(SFD )
2
2
SFD ;i'
OF (SFD 2)
OF 2
OF (SFD ) '
OF, =
(SFD )
1
OF=Offset SFD=Source to film distance
Inspector's Handbook 7-13

(TS + GAP) x OM SFD = new SFD
TS
TS=Depends on technique used 7
SFD=Source to film distance
GAP=Film to specimen distance
Dm( Efi) = Dm ( Efl)
Dn=Densitv Ef=Ex~osure factor
(TM or TS) X DS
MS
TM)=Thickness (TM if location marker is on TM) -
DS=Defect shift
MS=Marker shift
FSS = IS - (2 X PHs)
FSS=Focal spot size IS=lmage size
PHS=Pin hole size
Adding / Removing
Shielding
I
= Intensity after adding shielding
10 = Original intensity
HVL = # of Half-value layers added
Determining Shielding Required
h (A)
HVL =
I
.693
HVL = # of HVCs required to reduce intensity
In
= Natural
logrithm
lo = Original intensity
I = Desired intensity
Decay Fomula
A = New activity
Ao = Original known activity
n = TlHL
T = Time passed since known activity passed
HL
= Half-life of the isotope
I
= Intensity after removing shielding
10 = Original intensity
HVL = # of Half-value layers added
-
Common Half-Value Layers for IRl 92
d
Concrete 1.75"
Steel .500"
Lead .190"
Tungsten .130"
Kodak Radiographic Films
Type Speed Grain
R 8 Ultra fine
M 4 Extra fine
T 2 Extra fine
AA 1 Fine
Gamma Radiation
Exposure Calculator
Experienced Based Roentgen Factors (Steel)
Inspector's Handbook
DENS
I T Y
F 1.0
.652
1.3
2.6
I
L M
AA
T
M
1.5
.730
1.46
2.92
2.5
1.25
2.5
5.5
2.0
1.0
2.0
4.0
3.0 1.55
3.1
6.2
4.0
2.4
4.8
9.6

Magic Circles
D=Dose
DR=Dose rate
T=Time
Ef-Exposure factor
Ma=Milliamperage
T=Time
EeExposure factor
Ci=Curie
L
T=Time
Single Wall Exposure 1 Single Wall Viewing for Plate
I
SWE 1 SWV (PLATE)
1
Film
Pb "B"
TM = DESIGN MATERIAL THICKNESS
PENNY = BASED ON Tm
SHIM = BASED ON (1) WELD AND (1) ROOT
REINFORCEMENT
SFD
= BASED ON Ts
ENERGY
= BASED ON Ts
Inspector's Handbook
7- 15.

Single Wall Exposure 1 Single Wall Viewing for Pipe
I
SWE I SWV (PIPE) 1
Source *
Film
Pb "6"
TM = DESIGN MATERIAL THICKNESS
PENNY
= BASED ON Tm SHlM = BASED ON (1) WELD AND (1) ROOT
REINFORCEMENT
SFD
= BASED ON Ts
ENERGY = BASED ON Ts
Double Wall Exposure
1 Double Wall View (superimposed)
I
DWE 1 DWV I
Source *
Film I
Pb "B"
TM = DESIGN MATERIAL THICKNESS
PENNY = BASED ON (2) Tm
SHlM = BASED ON (2) WELD AND (2) ROOT
REINFORCEMENT
SFD
= BASED ON OUTSIDE OD
ENERGY
= BASED ON (2) Tm, (2) WELD AND
I
*
(2) ROOT REINFORCEMENTS I

Double Wall Exposure / Double Wall View (offset)
I DWE I DWV I
Source +%
-
Tm
F
Consumable lnsert
I markers I
I Film
I
Pb "B"
TM = DESIGN MATERIAL THICKNESS
PENNY
= BASED ON (2) Tm SHlM = BASED ON (1) WELD AND (1) ROOT
REINFORCEMENT
SFD
= BASED ON OUTSIDE OD
ENERGY
= BASED ON (2) Tm, (1) WELD AND
(1) ROOT REINFORCEMENT
-
Double Wall Exposure / Single Wall View
DWE I SWV
I
Consumable Insert
I
Film
Pb "B"
TM = DESIGN MATERIAL THICKNESS
PENNY
= BASED ON (1) Tm
FILM SIDE PENNY CHART
SHlM = BASED ON (I) WELD AND (1) ROOT
REINFORCEMENT
SFD
= BASED ON (1) Ts
u ENERGY = BASED ON (2) Tm, (1) WELD AND
(1) ROOT REINFORCEMENT
Inspectds Handbook

KILLER CARL
Magnesium
Aluminum
Penetrameter Material and Group Numbers
Titianium
.?1GROUP01 S-51.S-52,s-53
Carbon steel
Alloy steel
Stainless steel
Manganesse-nickel-aluminum bronze
S-I 1 C. S-11 D. S-36B, S-37A.
Aluminum bronze 1 1 . jGROUP 2
S-35, S-36
Nickel-chromium-
iron alloy V~GROUP 3 S-42, S-43. S-44
Nickel-copper alloys
Copper-nickel
alloys
Tin bronze
Gun metals
Valve bronze
Inspector's
Eandbook

7-20 Inspector's Handbook

- -
Inspector's Handbook

2% Penetrameter Quality Conversion Chart (X-RAY ONLY)

Inspector's Handbook 7-23

Inspector's Handbook

Basic Components of an Xray Tube
Highvoltage
Cathode Struc Power supply
Low- I ' / Filament 87 I/
, Electron
supply
Focusing
cup
voltage
power 7
Tube
1 envelope
X-ray beam
Types of Scatter Radiation
Test piece
L (a) Internal - (b) Side - (c) Back
scatter scatter scatter
Inspector's Handbook

Radiographic Film Interpretation
Arc strikes
DEFINITION: 4
Any localized heat-affected zone or change in the contour of the surface of the furished weld or adjacent
base metal resulting from .an arc or heat generated by the passage of electrical energy between the surface of the
finished weld, base material
and a current source, such as welding electrodes or magnetic particle inspection
electrodes.
RADIOGRAPHIC APPEARANCE:
A localized area, rounded or irregular, and generally found adjacent to the edge of the weld image on the
base metal.
The density of the indication appears lighter when the discontinuity is convex from the addition of
filler metal with arc strikes resulting from
SMAW process. The density of the indication appears darker when the
discontinuity is concave resulting from a gouging of the material with arc strikes resulting
from the GTAW or
SMAW processes.
CAUSES:
Not initiating the arc as required by the welding procedure.
Accidentally striking an arc on the completed weld or base material.
Engaging the magnetizing current prior to establishing fm contact with the test surface when using prods.
Moving or removing the prods from the test surface without disengaging the magnetizing current.
REMARKS/SPECIAL CONSIDERATIONS:
Arc strikes from welding and
MT are generally revealed and dispositioned upon acceptance Visual inspection.
However, welding arc strikes may
occur from another welding operation in the area after the
VTPT inspectior
and prior to the RT. Arc strikes occurring in this sequence have a random location and can be found on the we. Y
well as on the base metal.
Arc strikes fiomMT will be difficult to detect by RT.
Visual inspection should always be performed to confirm arc strikes.
Inspector's Handbook

Burn through
DEFINITION:
A. void or open hole extending into a backing ring or strip, fused A
oot or ac liacent b&e metal.
- -
IXAULWKAYHIC APPEARANCE:
m irregular localized area of darker density, often rounded,
gmerdlly found at the center of the weld image. If excessive globules of
the weld puddle resulting from the burn through, are present on the
inside of the weld joint, their appearance will have a lighter density due
to the additional weld metal. The nature of burn through is such that the
Using
' Improy
-- .
s edges
u.
a weld c
jerly pre
too slou
Idle.
- -- CL ---
of the in i may or may not be sharply defined.
:urrent h
paring t
.
CAUSE;
igher than allowed by the welding procedure.
t he tungsten electrode tip.
Using r a weldp d of travel will cause overheating of the
weld put
Improper nr up of the wela jomt (unacceptable root gap).
ECIAL ( IERATIONS :
- I 11G u~s~~l~~shing fea~urt; UGL~XII a burn through and a melt through
is that a burn through results in an open hole on the
ID of the pipe. Burn through most often occur during the welding of the root pass, although it is possible for this discontinuity to
be introduced during the welding of the second layer.
L Burn through frequently occur during weld repairs, especially when the repair cavity is at the root depth. I
Visual inspection should always be performed, if possible, to confirm bum through.
Inspector's Handbook
7-27

Concavity
I-ION:
RADIOGRAPHIC APPEARANCE:
CAUSE!
REMARKS/SPECIAL CONSIDERATIONS:
7-28 Inspector's Handbook

Crack crater
DEFINITION:
A linear rupture of metal under stress.
b,~~o~~~~ ~IRANCE:
Generally a star shaped indication with irregular, feathery? twisting lines of darker density oriented within a
weld crater. The discontinuity is usually shallow, therefore, the indication may not be as pronounced as indications
~UUU~GC.I from other types of cracking.
' Impr01
B Not ad
- T
CAUSES:
4 )f the welding arc by abruptly removing the arc.
4 meters of the welding procedure.
incomplete fillmg 01 ule weld crater.
REMAP
be emp
crater cr
.-. -- 3: -
I 2ONSIDERATIONS:
It is to hasized that although the discontinuity and resulting radiographic indication is generally star
shaped, acking does not always take this shape.
Random raaographic indications from crater cracking may be oriented in any direction to the weld axis.
Inspector's Handbook
7-29

Crack, longitudinal
(shown
in the root)
DEFINITION:
A linear rupture of metal under stress.
RADIOGRAPHIC
APPEARANCE:
Irregularly shaped, feathery, twisting lines of darker density
oriented along the axis of the weld.
CAUSES:
Improper fit-up of joint.
Contamination of base material.
Violation of the welding procedures.
REMARKS/SPECIAL CONSIDERATIONS:
Longitudinal
cracks can occur throughout the weld; in the centerline,
fusion lines and in the root. Cracking can, at times, be difficult to detect due to the geometric
principles
of the radiographic technique.

Crack, transverse
DEFINITION:
A linear
rwture of metal under stress.
u
&IDIOGRAPHIC APPEARANCE:
Irregularly shaped, feathery, twisting lines of darker density
oriented perpendicular to the axis of the weld. Transverse cracks are
generally tight discontinuities, therefore producing subtle indications
on
the radiograph.
CAUSES:
Transverse cracks are generally the result of longitudinal shrinkage
strains acting on weld metal of low ductility. Most commonly found in
weld joints having a
high degree of restraint.
REMARKSISPECIAL CONSIDERATIONS:
Cracks may be limited in size and completely within the weld metal,
but may also propagate fiom the weld metal into the adjacent heat
affected zone.
Orientation and subtleness of the discontinuity can, at times, be
difficult to detect due to the geometric principles of the radiographic
technique.
Cracking indications can be masked in the as-welded condition.
\v
Inspector's Handbook 7-3 1

Crater pits
indicatia
subtle to
DEFINITION:
An approximately circular surface condition extending into the weld in an irregular manner.
e
RADIOGRAPHIC APPEARANCE:
%e indication will appear as a circular dot with darker density, similar to porosity, in the root area of
lble insert welds. However, due to the irregular nature of discontinuity, the edge of the indication is usually
I~UL a5 uefined as porosity. The irregularity of the discontintinuity can produce a "halo" effect on the edge of the
guishing a crater pit fiom porosity. The radiographic indication from crater pits can range fiom
nced, depending on the severity of the pit.
CAUSE
Impr01
The in
Porosi
- xr:--.-1
. A"-
* Additi
confiinn;
~n, distin
I pronom
S :
per ten nination of the welding arc.
lhering to the parameters
of the welding procedure.
REMARKSISPECLAL CONSIDERATIONS:
s from crater pits
can be misinterpreted as porosity. ccur anywhere in the weld, while crater pits occur in the weld root area.
vlq11n~ mspecrion should always performed, if possible to confirm crater pits.
onal radiography, e.g. putting the indication in the sidewall or profile view, may be employed to assist in
ation of the discontinuity.
7-32 Inspector's Handbook

Incomplete fusion of a consumable insert
DEFINITION:
Tncomplete melting of the consumable insert without fusion and bonding to the base metal along one or
\c/
F :s of the consumable insert.
I
he axis I
n elonge
eld. The
RADIOGRAPHIC APPEARANCE:
i unifom ~ted band or localized bad of lighter density in the center of the weld image, oriented along
1 of the w L width of the band appears approximately equal to the diameter of the consumable insert.
material
The in
material
is not fu
CAUSE
Impro!
cation n
-- .
The indi lay appear in the following ways
The indcation rnav aDpear with both edges straight with abrupt density transitions fiom the insert area to the base
I area. TI rites lack of filling or blending to the base metal, with both sides of the insert not fused.
I dication pear with one edge having a smooth, gradual density transition fiom the insert area to the
base material
area and the other edge straight with an abrupt density transition fiom the insert area to the base lis indicates the former edge is blended with firsion into the adjacent base metal and the latter edge area. ll
sed.
of the ,
S:
~fit UP weld joint.
Using too low a welding current.
Using too fast of a travel speed.
An incorrect torch angle.
An improper motion or weaving technique of the torch.
REMARKS/SPECIAL CONSIDERATIONS:
b 8 Visual inspection should always be performed, where possible, to confirm incomplete fusion of the insert, when
viewed on radiographs.
Inspector's Handbook

Lack of fusion
DEFINITION:
Lack of complete fusion of some portion of the metal in a weld
joint with the adjacent metal. The adjacent metal may be either base
metal or previously deposited weld metal. When the discontinuity
occurs between a weld bead and the adjacent base metal, the term "lack
of sidewall hion" is often used, does not occur in the root.
RADIOGRAPHIC APPEARANCE:
Irregularly edged, or straight and irregularly edged lines of
darker density oriented along the axis of the weld. If lack 6f fusion
occurs between weld beads, both edges of the indication may
be
irregular as they indicate the weld puddle not fusing to the contour of the
previously deposited weld beads.
If the lack of fusion occurs between a
weld bead and base metal, one edge of the indication will be straight,
as
it indicates
the weld puddle not fusing to the prepared base meal.
Sometimes the lines are interspersed with darker density spots, of
varying shapes, indicating voids resulting from the lack of fusion.
CAUSES:
mcient welding current to melt the adjacent metal.
Too fast a welding speed of travel will not allow for fusion to the
adjacent metal.
Too fast a welding current to melt the adjacent metal.
Improper torch or electrode angle may prohibit melting of the adjacent metal.
. Improper placement of weld passes may cause a sharp valley to fonn.
Lack of proper access to the face of weld joint.
- -
Tightly adhering oxides resulting from improper cleaning of items to be welded.
REMARKS/SPECIAL CONSIDERATIONS:
Lack of fusion on the under bead side of the weld, lying
in a horizontal plane, tends to be undetectable but
often
the sides of lack of fusion lines tend to curl out of the horizontal plane and are recorded on the radiograph. - -
A distinguishing characteristic between lack of fusion and incomplete penetration is that lack of hion can occur
anywhere in the weld and incomplete penetration occurs at the weld root.
Inspector's Handbook

Lack of penetration
(left
-
nonnal fit-up, right - mismatch)
DEFINITION:
Lack of penetration of the weld through the thickness of the joint or penetration which is less
than
k specified.
straightr
incompl
GRAPHIC APPEARANCE:
Straight, fine edged lines of darker density oriented along the axis of the weld in the area of the root. The
less of both edges of the indication's image and location in the center of the weld image help to distinguish
ete penetration from lack of fusion.
CAUSE
Insuff
- I----
-
r--
In bot
cause a
Joints
elding current or to fast travel speed.
- Irnnroya wren or electrode angle to melt the root land.
h backing ring joints and joints to be welded from both sides, improper placement of initial weld pass may
sharp valley to form at the root weld.
from both sides, insufficient removal of the backside prior to welding.
s atthe7
on can b
weld roc
e promi
REMARKSISPECIAL CONSIDERATIONS:
~t and is always straight, as it is a RT indication of the actual weld joint preparation. The
nent or subtle depending on the severity of the discontinuity.
Inspector's
Handbook 7-35

Melt through
-.
DEFINITION:
A convex or concave irregularity on the s&ce of a backing ring
or strip,
through
hole.
fbsed root or adjacent base metal resulting from fusing comple
a localized region but without development of a void or open
RADIOGRAPHIC APPEARANCE:
A localized area, usually rounded, and generally found at the
center of the weld image. The density of the indication appears lighter
when the discontinuity is convex and darker when the discontinuity is
concave.
CAUSES:
Using a weld current higher than allowed by the welding procedure.
Improperly preparing the tungsten electrode tip.
Using too slow a welding speed of travel will cause overheating.
Improper fit up of the weld joint (unacceptable root gap).
REMARKS/SPECIAL, CONSIDERATIONS:
The entire thickness of metal is melted or re-melted and deforms, m
hole or void develops as with a burn through.
Melt through most often occurs during the welding of the root pass,
although it is possible for this discontinuity to
be introduced during the welding of the second layer. Visual
inspection should always be performed, if possible, to confirm melt through.
u
Inspector's Handbook

Offset
(misalignment/rnismatch, shown with LOP)
DEFINITION:
'L
Lateral misalignment of two butt joint members of equal
thickness.
RADIOGRAPHIC APPEARANCE:
Offset on piping weld joints can appear on the film in different
ways. The radiographic image is dependent upon the orientation of the
offset to the
beam of radiation. When the offset condition is parallel to
the
beam of radiation, the offset image may appear as an abrupt
density change, generally
half
my across the width of the weld image.
When the offset condition is perpendicular to the beam of radiation,
and the entire image of the item is on the film, the offset image will
appear in the sidewall or profile view, as lateral misalignment of the
members with a high-low effect of the pipes'
ID and OD.
CAUSES: Improper fit-up or fixturing may cause the members to be offset.
Improper welding block sequencing on the root pass.
REMARKSISPECIAL CONSIDERATIONS:
Visual inspection should always be performed to confii questionable offset conditions when viewed on
radiographs.
Inspector's Handbook
7-37

Oxidation
DEFINITION:
A condition resulting from partial or complete lack of purge of a surface which is heated during weldiv
resulting in formation of oxide on the surface. This condition may range from slight oxidation through the u
formation of heavy black scale to the extreme of a very rough surface having a rough crystalline appearance.
OGRAPHIC APPEARANCE:
Highly irregular, low density area,
with a wrinkled or sugared appearance in the center of the weld image.
The condition
may extend for the entire circumference of the weld when there is a complete loss of purge. The
condition may only
be localized, in one or more areas of the weld, occurring whenever the purge is partially
interrupted.
CAUSES:
*, Loss of internal purge gas resulting in an unshielded molten weld puddle on the ID.
High oxygen content in purge gas or path.
Moisture in the area of the weld, due to inadequate drying of the purge path, leakage, etc ...
REMARKSISPECIAL CONSIDERATIONS:
A visual inspection should always be performed, if possible, to confirm oxidation.
Oxidation generally occurs during the flowing of the weld root. However, this condition may occur during
welding if there is
a degree of root
reflow, loss of purge, or moisture present. Oxidation frequently occurs during
weld repairs.

Overlap (re-entrant angle)
DEFINITION:
The protrusion of weld metal beyond the weld toes or weld root.
sidewall
at the fu:
phic im2
r is not ;
-. .&+L ..
d -
or profi
sion line
",~IOGRAPHIC APPEARANCE:
3verlap conditions on the OD of piping butt weld joints should be an extremely me occurrence in as much
i ;factory VT and other surface inspections, such as PT or MT are required prior to RT. However, overlap
on ult: mternal weld surface consumable insert piping weld butt joints can appear on the film in different ways. The
I ige is dependent upon the orientation of the overlap to the beam of radiation. When the overlap
located in the sidewall or profile view, the overlap image will appear consistent
with that of Cul~vcnlrv WIU~ an abrunt density change at the fusion line of the weld root image. When the offset image is in the
! it will appear as roll over of the weld root reinforcement with an unsatisfactory blending
i weld root image.
- I
le view,
:ofthe
S:
I ow of a welding speed.
.roo low or too hi& of a welding current.
Me angle. ect torch
-
I or elecl
REMARKSISPECIAL CONSIDERATIONS:
Visual inspection should always be performed, where possible, to confm questionable root surface conditions
when viewed on radiographs.
Inspector's Harrdbook 7-39

Porosity
(right
- clustered porosity, bottom
left - distributed porosity, bottom
right
- aligned porosity in the root)
DEFJNITION:
Gas pockets or voids in weld metal.
RADIOGRAPHIC APPEARANCE:
Usually spherically shaped areas of darker density and may be
scattered throughout single pass welds or throughout several passes of
multiple pass welds. Although usually spherical
in shape, porosity may
also occur
as
nonspherical pockets and appear on the radiograph as
elongated voids, sometimes referred to
as "piping or wormhole
porosity". The density of the indication varies directly
with the diameter
or magnitude of the
pore.
CAUSES:
Faulty welding techniques such as using too long an arc with the
SMAW process.
Improper cleaning of the weld joint.
REMARKSISPECIAL CONSIDERATIONS:
None.
Inspector's Handbook

Root razorback condition
DEFINITION:
An oxide membrane, gray in color, with a sharp ridge or peak and ribs
fi.om the peak to the edge giving it a
L
'ierringbone effect. Also known as "reverse center line crease."
RADIOGRAPHIC APPEARANCE:
The image of root razorback is consistent
with that of convexity with an associated
herringbone appearance
and sharp peak at the center. The lightest density of the image is in the center and is dependent upon the height of
peaked condition. The density of the image gradually increases as the condition blends into the base metal.
CAUSES:
Moisture in the area of the weld. Moisture in the purge gas.
REMARKSISPECIAL CONSIDERATIONS:
This is one of the most common root surface defects encountered when welding NiCu and Ni-C-r-Fe.
Visual inspection should always be performed, where possible, to confm root razorback condition when viewed
on radiographs.
Inspector's
Handbook

Root surface centerline crease
DEFINITION:
An intermittent or continuous peripheral centerline concavity
fonned on the root surface.
I4
RADIOGRAPHIC APPEARANCE:
The image of centerline crease is consistent with that of concavity with an associated herringbone
appearance. If the crease has a notch or
a questionable blending condition at the center, the image will crease
oriented along the axis of the weld.
CAUSES: Thick cover pass over a consumable insert that had minor concavity. Excessive welding current.
REMARKSISPECIAL CONSIDERATIONS:
Visual inspection should always be preformed, where possible to confm questionable centerline crease when
viewed on radiograph.
Approved workmanship sample radiographs may be employed to evaluate centerline crease when a visual
inspection is not possible.
Inspector9s Handbook

Root surface concavity
DEFINITION:
A
depression on the root surface of the weld, which may be due to
L/
-pvity, internal purge or shrinkage.
RADIOGRAPHIC APPEARANCE:
The image of concavity may appear as intermittent elliptical areas
or elongated bands of darker
film density oriented along the axis of the
weld in the center of the weld image. The width of the image is consistent
with the weld root width. The darkest density of the concavity's image is
generally
in the center and is dependent
up6n the depth of the concavity.
The density of the image gradually decreases
as the concavity blends into
the base metal.
CAUSES:
.
Improper fit up of the weld joint.
Using too high of a'welding current, too slow of a travel speed, or
extremely high purge gas flow rate.
REMARKSISPECIAL CONSIDERATIONS:
Visual inspection should always be preformed, where possible to
confirm questionable concavity when viewed on radiograph.
Inspector's Handbook
7-43

Root surface convexity
I TION:
Reinforcement of tk root surface of a butt- ksed type weld.
I
4
RADIOGRAPHIC APPEARANCE:
The image of convexity may appear as intermittent elliptical areas or elongated bands of lighter film
density oriented along the axis of the weld in the center of the weld image. The widthof the image is consistent
with the weld root width. The lightest density of the convexity's image is generally
in the center and is dependent
upon the height of the convexity blends into the base metal.
CAUSES:
Using to low or high of a welding currert. Using too slow travel speed when welding.
REMARKS/SPECIAL CONSIDERATIONS:
Visual inspection should always be performed, when possible, to confirm questionable convexity when viewed
on radiographs.

Slag,
DEFINITION:
Non-metallic solid material entrapped in weld metal or
b'ptween weld metal and base metal.
. 2
RADIOGRAPHIC APPEARANCE:
Well defined, irregularly shaped, uniformly darker density
areas usually elongated along the axis of the weld.
' Impr01
between
-
Slag is
roods.
T
-- -
-
too low
welding
3n.
nx bead
+La L,,,
per inter
.--- ,---
(
unproper 111-up, sucn as maequate bevel of the joint sides.
Using a weldin ~t for the size of electrode.
Faulty : techniq 1 as wrong electrode position or
orientatic
I znt causing sharp valleys or undercutting
1
mpro] slag from the surface.
r a bypr
hus, slag
placemt
is.
kg currer
ues sucl
pass clel
oduct of
g inclusi~
. a,... a,.,
'the bur^
OnS are i
.. ... +I...-.
REMARKSISY~CIAL CUNSIOERATIONS:
ning of the flux covering on welding
asociated with the SMAW process.
Slag hlulw~v~la w -UJ ull~rlghout the weld, in the center of the
welcl-in fusion lines and in the r&t.
'v
Inspectds Handbook

Tungsten inclusion
DEFINITION:
Metallic tungsten inclusions in the weld deposit.
RADIOGRAPHIC APPEARANCE:
Irregularly shaped spots of low film density areas, usually
random in size and location. They are solid or liquid bits of tungsten
electrode from the TIG welding process that drop or are melted from the
electrode and become entrapped in the weld puddle. Tungsten inclusions
appear
as low or light density areas on the radiograph because of the
differences of radiographic absorption between the inclusion and
surrounding metal.
sten en is dnwr radi6graphically then the
surrounding metal and therefore absorbs more radiation. This, in turn,
allows fewer rays to reach the film.
CAUSES:
Overheating the tungsten electrode due to excessive current for the
particular electrode size.
DpfPctive tungsten electrode (flaking of particles).
ing the tungsten molten puddle. into the
--*-
m Dipp
REMARKSISPECIAL CONSIDERATIONS:
None.

Undercut
.tl
he base I
DEFINITION:
An intermittent or continuous groove on the external surface of
metal along the edge of the weld.
51
kAuluGWHlc MY~ARANCE:
a irregular, elongated area of darker density oriented along the
extamdl hion line of the weld image to the base metal.
using
8 using
rrn
filler me
An inc
too long
excessiv
.
.'a
cxccsslve welding current.
t an arc length will result in a gouging effect.
I ,e welding speed of travel.
w nen uslng me GTAW process, adding an -cient amount of
ectrode angle can cause a gouging effect.
acceptar
Visual
ice Visu
i inspect:
inspec
ion shou
. .
REMARKS/SPECIAL CONSIDERATIONS:
External undercut is readily revealed and dispositioned upon
:tion.
Id always be performed to confirm questionable
extema unaercut wnen viewed on radiographs.
- Inspector's Handbook 7-47

Undercut, root -
DEFINITION:
An intennittent or continuous groove in the internal surface of
the base metal, backing ring/strip along the edge of the root of the weld.
)GRAPHIC APPEARANCE:
An irregular, elongated area of darker density oriented along the
lnternai hion line of the weld image to the base metal.
filler m
mproper la up of the weld joint.
Excessive current during welding
When using the GTAW process, adding an insufficient amount of
incorrect electrode angle can cause
a gouging effect.
Radic
based c
. .
KEMARKS/SPECIAL CONSIDERATIONS:
evaluation of root undercut in backing ring joints can be
nanship sample radiographs as well as the use of slotted
7-48 ImyectoISs Handbook

Weld splatter
DEFINITION:
.
In arc welding, the metal particles expelled during welding which do not form a part of the weld.
iL/
, RADIOGRAPHIC APPEARANCE:
Small, rounded areas of lighter density generally found adjacent to the edge of the weld image on the base
metal.
CAUSES:
There will be some weld spatter when using the SMAW process. However, long arcing is a factor.
Lack of concentricity or damage to the electrode flux.
REMARKS/SPECIAL CONSIDERATIONS:
Weld splatter is most commonly found when the SMAW welding process is employed.
Weld spatter is generally revealed and dispositioned upon acceptance Visual inspection. However, weld spatter
may occur from another welding operation
in the area
after the acceptance VTPT inspections and prior to the RT.
Inspector's Handbook

. -
Caused bydit or tfconclitionis-,dean
preqlkbilwater ~radtad~wash
sy-rpliedlo~seclianwalerinpwzssa;dai.l&
t=lk*shutli-9po~ssar
dcMnrIfaKiperisfuse
filtersilhoaringwaterCnes
Probable Causes and Corrective Action for Automatic Film Processing
I I because lhey omr 3.14 ins&lled ar freshty deaned 1
CXtaFityorArtiliact Robablecause cclmchAclion
Densiitohii [email protected]&k~
Fw-
reaxrmendaliasla
dwekwand~used
IlqxcpdyNixedchemicals.
Fob#ins$uctionsfw
preperationof-
Qudityorm - ConectiveAclion
krprs>erlya4usledsuides ck&mm
npocessor guidedevicesand- -&
rdlersadhercomponents
Wabasbns Sbpcrhesbthgdes Besmalldlersareinthei
pcprposifias,andthatend
playis~fw~to
mfreely
7-50 Inspector's Handbook
see--
Fog v w-bhkh
F*bmperahre
recnmnendaticnsfor
devebper - used.
edae of a film
steak Associatedwlthtempod Longilknal-rn
wwk dfJms."delaysbedd"'
by'rrlervald15rrim&sar
mnfeeji-gofsuccesive
lhs,~resuKs~~d
sokaknsonprxessorrdlers
sgxsedbai.Wpea

Probable Causes and Corrective Action for Processed Radiographic Film
QudityaMbd Robable Cause Conac(iveAcbkn
wbklh Vwwith higherintensitylight
chedc~(timeand
radii intensity); if as
-,-wx==by
300hamore - Re&c%devebpnentbineor
developer-
Densftybb - Ched<v(tineand
radii 'ntensity); if a
sspecified,--
by40%orm
UlderdevebCment Lxreasedevebpnenttineor
devebperbmperahre.
QudityorArtihact RobaMeCause CcmdimAction
conkstlohigh Highsubjedamhst kweasebbe*
HghRnm UseaRnwith~~
ConbastblCNV LCMlSCkjeCfcOnbaSt ReduceW~
LCMlRncmbast Useafitnwithhighermbad
Urlerdevebpnent lnoease-tineor
deYebper-
-&(depleted
devebper)
FRelvmaltled?si
Fogonedgeor Defediecasette Dismdcassetbs
Replace&devebper
Maleridbetweensmen Rmmmlerid
and film
PoacjeiiniSon Testpiece-Msnctistance If possible, decreasetestpks
bbKl to-filmdiiifnaincrease
~ds&rxz
I
r. - - - -. . - -. - - . . . . . -
- .
Fog Ligtt~edcsindarkaxn \I\lilhdalawmun~~ I~fngerpints Touchinguwlevekpedh Washhaxkihu@yanddy,
,-
Yebvstail wdevebper ~devebper~
FaLrebusestopbathor Usesbpbabr,orrinSe
rinse lhroughly-c!=wb3
and*
shat
FcJd Spotlo large UsesmdfixdspAa
.klrxas?-
sbredfhhkpatdy AUachsbipdleadbbaded
protededfromm RnhdderandplacehRrr
SaXage-DeYebp-Rn
afterlmbthreeweeks;if
inagedsbipisevident
inpime radii Hi in
sexage area
hunidh/,oragases slkjed~gasesavapas - RecClcedevebpmentfineor
developer-
DevelcQer- --
~~pazssingDonctinspedtan~
F4ucshguntilfDdngis
Darkchhrnaks Fitnsplashedwith lmnersernhdevekperwith
devebperpriab care
Inspector's Handbook

About This Presentation

Slide Content

Tags

Categories

Download

Quick Actions

Statistics

Related Slideshows

NDT HANDBOOK

About This Presentation

Slide Content

Slide 1

Slide 3

Slide 4

Slide 5

Slide 6

Slide 7

Slide 9

Slide 10

Slide 11

Slide 12

Slide 13

Slide 14

Slide 15

Slide 16

Slide 17

Slide 18

Slide 19

Slide 20

Slide 21

Slide 22

Slide 23

Slide 24

Slide 25

Slide 26

Slide 27

Slide 28

Slide 29

Slide 30

Slide 31

Slide 32

Slide 33

Slide 34

Slide 35

Slide 36

Slide 37

Slide 38

Slide 39

Slide 40

Slide 41

Slide 42

Slide 43

Slide 44

Slide 45

Slide 47

Slide 48

Slide 49

Slide 50

Slide 51

Slide 52

Slide 53

Slide 54

Slide 55

Slide 56

Slide 57

Slide 58

Slide 59

Slide 60

Slide 61

Slide 62

Slide 63

Slide 64

Slide 65

Slide 66

Slide 67

Slide 68

Slide 69

Slide 70

Slide 71

Slide 72

Slide 73

Slide 74

Slide 75

Slide 76

Slide 77

Slide 78

Slide 79

Slide 80