By reading this ppt we can know that how t the calibration of glassware is done in the industry or laboratory before doing any experiment in lab
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Calibration of Glassware
Prepared BY:
AMIT KUMAR KUSHWAHA
I.D NO: 17BPH088
subject: Practice school
Sub code:BP706ps
B.PHARM (7
th
SEM)
SHUATS/SIHAS
16 November
2020
1
CONTENTS
•Introduction
•What is Calibration ?
•Why the Calibration so important ?
•Types of Glassware
•Calibration of Glassware
•What is Tolerance ?
•Procedure for Calibration of Glassware
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Introduction:
The ability of all measuring instruments to measure accurately
and reliably is to be proved, to get meaningful results. For
this, the results of measurement are to be compared with
higher standards.
The instruments, gauges to be used for measurement should
be of known accuracy in order that the results obtained are
meaningful.
In order to identify the errors and rectification of errors, the
instruments are compared with masters or standards. This act
of comparison is known as calibration.
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What is Calibration?
The process of comparison of a device
with unknown accuracy to a device with a
known, accurate standard to eliminate any
variation in the device being checked is
calledCalibration.
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Why the calibration so Important?
Calibration defines the accuracy and quality of measurements
recorded using a piece of equipment.
Over time there is a tendency for results and accuracy to ‘drift’
when using particular technologies or measuring particular
parameters such as temperature and humidity.
To be confident in the results being measured, there is an
ongoing need to maintain the calibration of equipment
throughout its lifetime for reliable, accurate and repeatable
measurements.
The goal of calibration is to minimise any measurement
uncertainty by ensuring the accuracy of test equipment.
Calibration quantifies and controls errors or uncertainties
within measurement processes to an acceptable level.
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Calibration of glassware
Glassware is commonly calibrated using a
liquid of known, specific density, and an
analytical balance.
The procedure is to determine the mass of
liquid the glassware will hold, and to divide this
mass of liquid by the density of the liquid,
obtaining the corresponding volume of liquid.
Density is affected by temperature, so it is
necessary to measure the liquid temperature
and look up appropriate density values.
While the above procedure will suffice for
items calibrated “TC” (to contain), it is not
useful for those items calibrated “TD” (to
deliver).
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Types of glassware
Type A Glassware Type B Glassware
•Economy Grade.
•Have high accuracy.
•Use for quantitativework.
•It always have a large “A”
prominent near the label.
•Studentgrade.
•Have low accuracy.
•Use for Qualitative & semi
quantitative.
•Glassware without “A” label is
class “B”.
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What is Tolerance?
Tolerance is the greatest range of variation that can be
allowed for an instrument or Equipment.
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How to determine Tolerance Interval
To determine the tolerance interval in a measurement ,add
and subtract one-half of the precision of the measuring
instrument to the measurement.
For example: If a measurement made with a 10ml pipette is
5.6 ml and the pipette has a precision of 0.1ml, then the
tolerance interval in this measurement is 5.6 plus minus
0.05ml,or from 5.55ml to 5.65ml.
Any measurements within this range are “tolerated” or
perceived as correct.
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Procedure for Calibration of
Glassware(Type A and Type B)
Calibration of Type A Glass Apparatus:
•These are used directly for analysis purpose and are
received with calibration certificate.
Calibration of Type B Glass Apparatus:
For Volumetric Flask:
•Weigh accurately a previously dried volumetric flask.
•Make up the volumetric flask up to the mark with
purified water.
•Wipe dry the outside of the volumetric flask and then
weigh.
•Find out the weight of water by subtracting the empty
weight ofvolumetric flask from total weight (Empty
volumetric flask weightand water weight).
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Procedure for Calibration of
Glassware(Type A and Type B)
•Calculate the volume by taking correction factor 0.99602 gm(i.e.
1mL of purified water at 25°C = 0.99602 g) and Record the
observationsin Calibration Format as Given Below.
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Observation I:
Weight of pre-weighed dry, empty, volumetric flask / Beaker, in gm
(W1):________________ gm
Weight of volumetric flask/ Beaker and water, in gm
(W2):__________________ gm
Weight of water, in gm(W3): = (W2 –W1) = ________________________ gm
Observed volume of the glassware:W2 –W1= _________________ml
D
Where: D = 0.99602 (Density of water at 25 °C in gm/ml)
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For pipette and Burette
•Weigh accurately previously dried empty beaker.
•Fill the pipette and burette with purified water up to
the mark withthe help of bulb.
•Wipe dry the outside of the transfer pipette & burette
and thentransfer the water in pre-weighed beaker
and weigh.
•Find out the weight of water by subtracting the empty
beaker weightfrom total weight (Empty beaker
weight and water weight).
•Calculate the volume by taking correction factor
0.99602 gm(i.e. 1mL of purified water at 25°C =
0.99602 g). Record the observationsin Calibration
Format asgiven below: 16 November
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Observation II:
Weight of pre-weighed dry, empty, volumetric flask / Beaker, in gm
(W1):________________ gm
Weight of volumetric flask/ Beaker and water, in gm
(W2):__________________ gm
Weight of water, in gm(W3): = (W2 –W1) = ________________________ gm
Observed volume of the glassware:W2 –W1= _________________ml
D
Where: D = 0.99602 (Density of water at 25 °C in gm/ml)
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Continue….
•Calculate the difference between Labeled Volume and average of
observed volume of glassware as per following formula
•Difference in Volume = Labeled Volume –Average of Observed
Volume
•Ensure that the difference in volume shall be within the tolerance
limits as listed in Table I
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Table of Glassware Tolerance
Volumetric
flask
Labeled
Volume, in
mL
10 25 50 1002002505001000
Tolerance, ±
mL
0.040.060.100.160.200.240.300.60
Transfer
Pipettes
Labeled
Volume, in
mL
1 2 5 10 2025 50100
Tolerance, ±
mL
0.0120.0120.020.040.060.060.100.16
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Table of Glassware Tolerance
Burettes
Labeled
Volume, in
mL
1 2 5 10 2025 50100
Tolerance, ±
mL
0.0120.0120.020.040.060.060.100.16
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Continue….
•When the volumetric glassware do not comply with the
requirement as specifiedabove, the volumetric glassware
should return back.
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References:
•https://pharmapathway.com/calibration-and-handling-of-
glassware-class-a-and-class-b/
•https://learnmech.com/calibration/
•https://www.pharmaqualification.com/2019/10/calibration-of-
glassware.html
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