Sokkia 30R Series Operator's Manual page 35

4. Turn 90° and center the bubble
Turn the upper part of the
instrument though 90°.
The plate level is now
perpendicular to a line between
levelling foot screws A and B.
Center the air bubble using
levelling foot screw C.
5. Turn another 90° and check
bubble position
Turn the upper part of the
instrument a further 90° and check
to see if the bubble is still in the
center of the plate level. If the
bubble is off-center, perform the
following:
a.Turn levelling foot screws A and
B equally in opposite directions
to remove half of the bubble
displacement.
b.Turn the upper part a further
90°, and use levelling foot screw
C to remove half of the
displacement in this direction.
Or adjust the plate level.
"26.1 Plate Level"
6. Check to see if the bubble is in the
same position in any direction
Turn the instrument and check to
see if the air bubble is in the same
position in all directions.
If it is not, repeat the levelling
procedure.
7. SETTING UP THE INSTRUMENT
27