Chain Surveying: Learn Procedure, Equipments Used, Errors and Corrections here!

A triangle is said to be a well conditioned triangle if all intersections of lines are clear for the purpose of plotting. No angle of a well conditioned triangle should be less than 30° or greater than 120°. An equilateral triangle is regarded as the most appropriate well conditioned triangle

 Chains can be read easily and can be repaired on the field itself. But using chains for measurements comes with certain disadvantages too. If the chain becomes heavy, it tends to sag thereby requiring correction and chains can be employed only for ordinary works

Error = Measured distance - Correct distance
     and, Correction = Correct distance - Measured distance, this implies that error = -correction.

Field works in Chain Surveying include : Recoinnanse, Marking of stations, Running survey lines and Taking offsets. 

Optical square, French square, Cross staff are used to measure right angles. French square is also used to measure 45°, 90° and 135°.