Line-Of-Sight - CST/BERGER SAL20N Instruction Manual

CALIBRATION
Your Automatic Level has been factory calibrated; however, you should
occasionally check your level for errors caused by shipment or rough han-
dling.
Compensator lock button
Check the compensator for proper operation before use or anytime the oper-
ation of the instrument is in question. Push and release the compensator
lock button to shake the compensator. The compensator should return to the
exact horizontal position sighted before the lock button was pressed.
Circular bubble vial
Center the vial bubble using the leveling screws, then rotate the instrument
180°. The bubble should remain centered (Fig. 6). If the bubble moves out of
center, the vial needs adjustment (Fig. 7).
Turn the leveling screws to bring the bubble halfway to center (Fig. 8). Using
the Allen wrench, turn the two vial adjustment screws to center the bubble
(Fig. 9).
Repeat the above procedure until the bubble remains centered when the
level is rotated 180°.

Line-Of-Sight

The line-of-sight needs to be horizontal within 3 mm of level to be accurate.
Set up and level the instrument on a tripod midway between two leveling
rods set approximately 30m to 50m apart. Sight rods A and B; the height
readings are a1 and b1 (Fig. 10). The value "H" is equal to (a1 – b1). Move the
instrument to within 6 feet (2m) of rod A and re-level. Again sight rods A and
6 • PAL/SALN AutoLevel