17 CHECK AND ADJUSTMENT
17.3 Checking/Adjusting the Theodolite Functions
zPointers on the Adjustment
1) Adjust the eyepiece of the telescope properly prior to any checking operation which involves
sighting through the telescope.
Remember to focus properly, with parallax completely eliminated.
2) Carry out the adjustments in the order of item numbers, as the adjustments are dependent one
upon another. Adjustments carried out in the wrong sequence may even nullify previous
3) Always conclude adjustments by tightening the adjustment screws securely (but do not tighten
them more than necessary, as you may strip the threads, twist off the screw or place undue stress
on the parts).
Furthermore, always tighten by revolving in the direction of tightening tension.
4) The attachment screws must also be tightened sufficiently, upon completion of adjustments.
5) Always repeat checking operations after adjustments are made, in order to confirm results.
zNotes on the Tribrach
Note that the angle measuring precision may be effected directly if the tribrach has not been installed
1) If any leveling screw becomes loose and slack or if collimation is unstable due to the looseness of
leveling screws, adjust by tightening the adjusting screws (in 2 places) installed over each leveling
screw with a screwdriver
2) If there is any slack between the leveling screws and the base, loosen the set screw of the holding
ring and tighten the holding ring with adjusting pin, until it is properly adjusted. Re-tighten the set
screw on completing the adjustment.
Leveling screw Holding ring Set screw