B; these height readings are a2 and b2 (Fig. 11).
If a1 – b1 = a2 – b2 = H, the line-of-sight is horizontal. If not, the level should
be adjusted as follows.
Because the instrument is set halfway between A and B, any error in the
line-of-sight causes both readings to be erroneous by the same amount.
Error "e" cancels out, so the value a1 – b1 = H is correct. Therefore, a2 – H =
b3, the adjusting value.
To adjust, unscrew the eyepiece cover. Turn the adjusting screw with the
adjusting pin (Fig. 12) until the horizontal cross hair gives the reading b3, on
rod B. Repeat the above Procedure until {(a1-b1) – (a2-b2)} </= 3 mm.
MAINTENANCE
Care must be taken to maintain the accuracy of the instrument.
•
After each use, the instrument should be wiped clean and kept in its
carrying case.
•
Remove dust from the lenses with a soft brush or a nonabrasive wipe.
Never touch the lenses with your fingers.
•
Store the instrument in a dust-free area with low humidity.
•
A bag of silica gel dryer is included with each instrument; if it has
stopped working effectively, bake it to remove moisture or replace with
a new bag.
•
Any damage to the instrument must be repaired by a
CST/berger Authorized Service Center.
PAL/SALN AutoLevel • 7