Aquaculture Engineering

Levelling - Levelling instruments:

Unit 1- Surveying

Levelling

Levelling instruments:
The instruments commonly used in direct levelling are

• A level
• A levelling staff

A level: The purpose of a level is to provide a horizontal line of sight. A level consists of the following four parts.

• A telescope – To provide line of sight
• A level tube – To make the line of sight horizontal
• A levelling head – To bring the bubble in its centre of run
• A tripod – To support the instrument

There are four types of level

• Dumpy level
• Wye (Y) level
• Reversible level
• Tilting level