Surveying instruments with their uses
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This document provides an overview of surveying instruments. It defines surveying as determining relative positions of objects on Earth's surface by measuring horizontal distances and preparing maps. Common instruments are then described, including chains of various types for measuring distance, tapes, clinometers for measuring angles of inclination, staff rods, ranging rods, compasses, optical squares, Abney levels, auto levels, theodolites, total stations, tripods, scales, and plane tables. Additional instruments mentioned include passometers, pedometers, odometers, perambulators, line rangers, cross staffs, alidades, sextants, French cross staffs, geodimeters, fathometers, ghat tracers, substense bars,
Surveying instruments with their uses
- 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 Instruments 5 Different type of instruments used in surveying are • Chain Chain is an instrument used to measure linear distance in surveying.
- 8. 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.
- 9. 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
- 10. 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.
- 11. 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
- 12. Tapes Accurate measurements are carried out through tape in survey. Lighter in weight. Easier to handle than chain Types Cloth or linen tape Invar tape( Metallic-nickel) Steel tape(Cloth wire) Fiberglass tape
- 13. Clinometer An instrument used by surveyors in order to measure an angle of inclination or elevation.
- 15. • Staff rod/ Levelling rods Used with auto level in measuring the levels of different points or objects. 15
- 16. • Ranging Rods These rods are used in surveying for stationing and ranging of lines. For Ranging atleast 3 rods • Reflector/Prism Used in total station Surveying as shown in figure 16
- 17. • Compass A compass is an instrument used for navigation and orientation that shows direction relative to the geographic "cardinal directions i.e. (North, South, East and West)", or "points". Compass are of different types. 1. Trough Compass 17
- 18. 2. Prismatic Compass This Prismatic Compass is used for the purpose of measuring magnetic bearings. -whole circle bearings. -0 degree on south pole. -0 to 360 degrees 18
- 19. Surveyor Compass This compass is also used fro measuring bearing with the North and south poles. The bearing are shown in quadrants. For Reduced Bearings. 0-90 degrees 19
- 20. 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.
- 21. Abney level A kind of clinometer consisting of a sighting tube, spirit level, and graduated scale.
- 22. • Planimeter The Planimeter is a drafting instrument used to measure the area of a graphically represented planar region. The region being measured may have any irregular shape, making this instrument remarkably versatile. 22
- 23. • Bags Used for keeping the instruments like prism etc. safe. • Field Book Used for entering the field data (measurements). 23
- 24. • Auto level Used in levelling process of survey. 24
- 25. • Theodolite Used for measuring horizontal and vertical angles. Most precise instrument. Accuracy upto 10-20 seconds • Total Station Used for measuring angles, Coordinates, levelling etc. 25
- 26. • Tripod Used for setting out of Instruments like Auto level, theodolite, total stations etc. • Pegs Used for stations point or used in setting of curves. 26
- 27. • Scales Used in plotting of surveying works 27
- 28. • PlaneTable Used in plan table surveying 28
- 29. • Plumb bob Used for verticality and point centering. 29
- 30. 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.
- 31. 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.
- 32. Extra Instruments. Line ranger Cross Staff Alidade Sextant French Cross Staff Geodimeter Fathometer Ghat Tracer Substense Bar Tellurometer Gradiometer. Tachometer