Aquaculture Engineering

Chain surveying - Instruments used for setting out right angles

Unit 1- Surveying

Chain surveying

Instruments used for setting out right angles

There are several types of instruments used to set out a right angle to a chain line, the most common being Cross staff, Optical square and Prism square.

There are three types of cross staff namely

• Open cross staff
• French cross staff
• Adjustable cross staff