1. Position b 90 0 to position a Bubble still follows LEFT THUMB

2. Position b 90 0 to position a

3. Manufacturer’s Recommendation for Setting up a Theodolite 6)Fine level the theodolite using the PLATE level bubble tube and foot SCREWS Position a) align the plate level bubble tube with two foot screws. Centre the bubble by rotating the two foot screws in opposite directions. The bubble follows the LEFT thumb. Position b) align the plate level bubble tube with the third foot screw. i.e. 90 0 from position a) Centre the bubble by rotating the the third foot screw (only) The bubble follows the LEFT thumb. REPEAT positions a) and b) until the bubble stays in the centre 7)Look through the optical plummet again. Loosen the centring screw holding the theodolite to the tripod and slide the theodolite over the tripod HEAD until the reticle is over the station. REPEAT 6) and 7) until the plate level bubble is central AND the optical plummet is over the survey station. 8)Check the plate level bubble in positions c) and d) - 90 0 from position a) and b) and if necessary remove half the bubble drift to FREEZE the bubble.

4. Position c Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions

5. Position c Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions (using two footscrews)

6. Position d Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions

7. Position d Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions (using one footscrew) The bubble is now “FROZEN” in 1.5 divisions to the left and should stay this much out wherever it is rotated to.

8. Position d Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions (using one footscrew) The bubble is now “FROZEN” in 1.5 divisions to the left and should stay this much out wherever it is rotated to.

9. Position d Bubble drift is 3 divisions Remove half the drift i.e. 1.5 divisions (using one footscrew) The bubble is now “FROZEN” in 1.5 divisions to the left and should stay this much out wherever it is rotated to.

10. REPEAT positions a) and b) until the bubble stays in the centre Manufacturer’s Recommendation for Setting up a Theodolite 6)Fine level the theodolite using the PLATE level bubble tube and foot SCREWS Position a) align the plate level bubble tube with two foot screws. Centre the bubble by rotating the two foot screws in opposite directions. The bubble follows the LEFT thumb. Position b) align the plate level bubble tube with the third foot screw. i.e. 90 0 from position a) Centre the bubble by rotating the the third foot screw (only) The bubble follows the LEFT thumb. 7)Look through the optical plummet again. Loosen the centring screw holding the theodolite to the tripod and slide the theodolite over the tripod HEAD until the reticle is over the station. REPEAT 6) and 7) until the plate level bubble is central AND the optical plummet is over the survey station. 8)Check the plate level bubble in positions c) and d) - 90 0 from position a) and b) and if necessary remove half the bubble drift to FREEZE the bubble. Check centring and repeat 7) and levelling until The theodolite has been FINELY LEVELLED AND CENTRED OVER THE SURVEY STATION. It is now ready for referencing to a BACK SIGHT for either measuring or setting out angles.