ABSTRACT

A line diagram of a dumpy level is shown in Fig 1. The instrument is set up on the tripod approximately level. It is then set accurately by means of the levelling screws as follows:-

Turn the telescope parallel to any two screws, e.g. ‘A’ & ‘B’ Fig 2. and adjust for level by turning screws ‘A’ & ‘B’. Turn telescope through 90° and adjust for level by turning screw ‘C’ Fig 3. Turn back to original position and check.