survey instruments 02-Dumpy level and Tripod

Dumpy level and Tripod Invention In 1832, English civil engineer William Gravatt, who had worked with Marc Isambard Brunel and his son Isambard on the Thames Tunnel, was commissioned by Mr. H.R. Palmer to examine a scheme for the South Eastern Railway's route from London to Dover. Forced to use the then conventional Y level, during the works Gravatt devised the more transportable and easier to use dumpy level.   What is dumpy level  A dumpy level is used to establish or check points in the same horizontal plane. It is used in surveying and building to transfer, measure, or set horizontal levels. But Dummy level is the most...

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Traditional survey - chain survey -02

  Chain Survey Chain survey is the simplest method of surveying. In this survey only measurements are taken in the field, and the rest work, such as plotting calculation etc. are done in the office. This is most suitable adapted to small plane areas with very few details. If carefully done, it gives quite accurate results. The necessary requirements for field work are chain, tape, ranging rod, arrows and some time cross staff. Principles of Chain Survey A triangle is a simple figure which can be plotted from the lengths of three sides even if the angles are not known. In chain survey, the area to be surveyed is divided into a framework...

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survey instruments 01-Tapes

Tapes Tapes are used in surveying to measure horizontal, vertical, and slope distances. They may be made of a ribbon or a band of steel, an alloy of steel, cloth reinforced with metal or synthetic materials. Tapes are issued in various lengths and widths and graduated in a variety of ways. I. Cloth or Linen Tape II. Metric Woven Metallic Tape III. Metric Steel Tape IV. Invar Tape V. Synthetic Tape (adsbygoogle = window.adsbygoogle || []).push({}); I. Cloth or Linen Tape It is made of varnished strip of woven linen 12 to 16 mm wide with a brass handle at zero ends, whose length is also included in the length of the tape. The tape...

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Traditional survey - chain survey-01

Chain The chain is a instrument and unit, using for surveying and measure distances. The chains used in surveying are generally of the following types. I. Gunter’s chain II. Engineer’s chain III. Metric chain IV. Steel Band Chain V. Revenue Chain (adsbygoogle = window.adsbygoogle || []).push({});           I. Gunter’s chain surveyor’s chain, also called Gunter’s chain, measuring device and arbitrary measurement unit still widely used for surveying in English-speaking countries. Invented by the English mathematician Edmund Gunter in the early 17th century, Gunter’s chain is exactly 22 yards...

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