Pentax ETH-310 - Manual (Page 38)

38
Adjustment
Center the plate vial bubble.
Rotate the instrument 180°, move the bubble half way back to
the center by operating a leveling screw which is located parallel
with the plate vial.
Rotate the vial adjusting screw with the adjusting pin and position
the bubble in the center.
Repeat procedure again to confirm. 1
2
3
4