Page 12 - ebook_soil engineering practical workbook_15112021

1.5.1.1 Setting Up The Level

- Release the clamp screw of the instrument

- Hold the instrument in the right hand and fix it on the tripod by turning

round only the lower part with the left hand.
- Screw the instrument firmly.
- Bring all the foot screws to the center of its run.

- Spread the tripod legs well apart.
- Fix any two legs firmly into the ground by pressing them with the hand.

- Move the third leg to the right or left until the main bubble is
approximately in the center.

- Then move the third leg in or out until the bubbles of the cross-level is
approximately in the center.

- Fix the third leg firmly when the bubbles are approximately in the
centers of their run.

1.5.1.2 Levelling Up

- Place the telescope parallel to a pair of foot screws.

- Bring the bubble to the center of its run by turning the foot screws

equally either
- both inwards and both outwards.
- Turn the telescope through 90º so that it lies over the third foot screw.

- Turn this third foot screw so that the bubble corners to the center of its
run.

- Bring the telescope back to the original position without reversing the
eye-piece and object glass.
- Repeat the above operations until the bubble remains in the center of

its run in both the positions.
- Turn the telescope through 180º and check whether the bubble remains

central.

4 | Soil Engineering Practical Workbook