Description

Surveying Chains:

The chain is used to measure the distance on the ground. It gives much more accurate measurement as compared to tape.

A chain is a surveying instrument that is made up of connecting links of galvanized mild steel. The mild steel wire is bent into a ring and joined to each other with three small circular or oval rings. Each connecting link measures 20 cm.

A tally marker or a special joint is also installed sometimes to mark the distance of 5 meters.

The total length of the chain is 20 meters or 30 meters, which also includes a brass handle on each end. The handles are provided with swivel joints for they can be easily turned during surveying without being twisted.

Some of the commonly used chains in surveying are

1. Metric chain– Widely used and available in lengths of 5, 10, 20, and 30 meters.
2. Surveyor’s chain: Length is 66 feet and has 100 links Widely used for land measurement as 10 square chains make 1 acre.
3. Engineer’s chain: Length is 100 feet and has 100 links. Brass tags are installed at every 10 feet.
4. Revenue chain: Length is 33 feet and has 16 links.

A chain has to be tested if it is accurate and necessary adjustments are made if not.