Surveying instruments with their uses

all the instruments used in surveying are described in this

1. Surveying 1 Awais Ahmed Mirza Lecturer (Bps-18) @ Civil Engineering Department, Mehran U.E.T., Jamshoro.

2. Outcomes: You will have knowledge about Surveying and Surveying’s Intruments that are used in fields. You will learn different new terminologies about surveying. This lecture would also help you for objective oriented study. You will have to memorize some constants.

3. Define Surveying? The art of determining the relative positions of different objects on the surface of earth or beneath the surface of earth, by measuring the horizontal distances between them ,and by preparing a map to any suitable scale is called surveying.

4. Introduction to various Surveying Instruments: In Surveying, we measure horizontal distances, horizontal angels, vertical angles, levels and etc.

5. Surveying Instru m ents E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 5 Di f ferent type of ins t ru m ents used in surveying a r e C h ain Chain is an instru m ent used to m easure lin e a r dista n ce in surveyin g .

6. Chains The chain is composed of 100 or 150 pieces of steel /iron which are also called links. The ends of each link are bent into a loop and connected together by means of three oval rings which give flexibility to the chain. The joints of the links are usually open, but in the best chains they are mostly welded. The ends of the chain are provided with brass handless for dragging the chain on the ground, so that the chain can be turned round without twisting. The out side of the handle is the zero point or the end point of the chain and the length of the chain is measured from the out side of the one handle to the out side of the other . The length of the link is the distance between the centers of the two consecutive / continuous middle rings.

7. Types of Chain Gunter’s Chain/ Suveyor’s Chain It is 22 yards or 66 feet long and is divided into 100 links; the length of each link is 0.66 feet or 7.92 inches. Formerly it was mainly used in land surveying. It is very convenient for measuring distances in miles and furlongs and for measuring land when the unit of area is an acre on account of its simple relation to the mile and acre. 10 Gunter’s chain = 01 furlong 1 furlong= 660ft 80 Gunter’s chain = 01 mile 10 Square Gunter’s chain = 01 acre

8. Revenue chain: This chain is commonly used for measuring fields in cadastral survey. It is 33 feet long and is divided into 16 links and each link is 2.0625 feet long. Engineering or Engineer’s Chain : The engineering chain is 100 feet long and is divided into 100 links; each link is 01 feet long. It is used in all engineering surveys. When long links are measured, it is more accurate than the Gunter’s chain, because of its greater length. The distances measured with the engineer’s chain are recorded in feet and decimals .

9. Metric Chain: Those countries in which the meter is the unit of length, chains of 10, 20 and 30 meters are commonly used. The 20-meter chain which is in most common chain use is divided into 100 links. 30 meter chain into 150 links Each link 20 cm In 1 meter =5 links

10. Tapes Accura t e m easure m ents are ca r r i ed out th r ough tape in surve y . Lighter in weight. Easier to handle than chain Types Cloth or linen tape Invar tape( Metallic-nickel) Steel tape(Cloth wire) Fiberglass tape

11. Clinometer An i nst ru m en t use d b y surveyors i n o rder to m eas u re a n ang l e of i n cl i n a tion o r e l ev a tion.

12. Sta f f r o d / L e vell i ng r o d s Used wi t h auto l e vel i n m ea s u r ing the l e vels of di f ferent p o in t s or o b jec t s . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 15

13. Ranging Rods These rods are used in s urve y ing for sta t io n ing a nd ran g ing of l i ne s . For Ranging atleast 3 rods Reflec t or/P ri sm Used in to t al s t a t i o n Surveying as shown in figure E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 16

14. Compass A compass is an instr u m ent used for naviga t i o n and or i e n ta t ion that shows dire c tion rel a tive to t h e g e ograp h ic "cardi n al d ire c tions i.e. (Nor t h, South, East and W es t ) " , or "po i nt s ". C o m pass are o f di f ferent type s . 1. T r ough Compass E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 17

15. 2. Pri s mat i c Compass This Pris m at ic Co m pass is used f or t h e pur p ose o f m easur i ng m agne t ic bea r ing s . -whole circle bearings. -0 degree on south pole. -0 to 360 degrees E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 18

16. S u rve yo r Comp a ss Th i s co m pa s s is a l so us e d fro m e a su r i n g be a r i ng wi t h t h e Nor t h a nd sou t h po l e s . The be a r i ng a r e shown in qu a d r an t s. For Reduced Bearings. 0-90 degrees E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 19

17. Optical Square A small hand instrument used by surveyors for laying off a right angle by means of two mirrors set at an angle of 45 degrees.

18. Abney level A kind of clinometer consisting of a sighting tube, spirit level, and graduated scale.

19. Plan i met e r The Pla n imeter is a dr a fting instr u m ent used t o m easure t h e area of a grap h ic a lly represen te d planar region. The re g ion b e ing m easured m ay have any i r regu l ar shape, m aking t h is instru m ent re m arka b ly versa t ile. E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 22

20. Bags Used for keep i ng the ins t ru m ents l i ke pr i sm et c . safe. Field B o ok U sed for ent e r i ng the field data ( m easure m ent s ) . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 23

21. A u to lev e l Used in lev e lling process of surve y . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 24

22. T h eodol i te Used for m easur i ng hor i zont a l and vert i c a l angl es . Most precise instrument. Accuracy upto 10-20 seconds T otal Station Used f or m easur i ng angles, Coordinate s , lev e lling et c . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 25

23. T ripod Used f or set t ing ou t o f Instru m ents l ike A u to l e v el, theod o lit e, to t al st a t i ons et c . Pegs Used for st a t i ons point or used in se t t i ng of curve s . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 26

24. Scales Used in plot t ing o f surveying w o rks E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 27

25. Plan e T able Used in plan tab l e surveying E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 28

26. Plumb bob Used for verticality and p oint centerin g . E n g r .S h ams Ul I s lam (s h ams@ c e c os. e d u .p k ) 29

27. Instruments for measuring horizontal distances: Passometer : An instrument, shaped like a watch that is used to count the number of a person's steps. Pedometer: An instrument for estimating the distance travelled on foot by recording the number of steps taken.

28. Odometer An instrument for measuring the distance travelled by a wheeled vehicle. Perambulator A  surveyor's  wheel, also called a clickwheel , hodometer , waywiser , trundle wheel, measuring wheel or  perambulator  is a device for measuring distance.

29. Extra Instruments. Line ranger Cross Staff Alidade Sextant French Cross Staff Geodimeter Fathometer Ghat Tracer Substense Bar Tellurometer Gradiometer. Tachometer