30
? Check and Adjust the optical plummet
To superpose the optical axis of the plummet and the vertical axis, adjustment for
the plummet is neccessary, otherwise the vertical axis will not be on the true anchor
point when the aim begins.
Inspection
? Mount the instrument on the tripod and place a sheet of paper with a cross on it
under the instrument.
? After adjusting the focus of the optical plummet, move the paper to center the
cross of the crosshair in the field of view.
? Turn the collimator 180º, observe the superposed degree of the center mark and
the cross.
? If the center mark of the optical plummet and the cross of the hair keep
superposed when turning the collimator, adjustment is unnecessary. If not, adjust it.
Adjustment
? Turn counterclockwise and remove the adjusting screw cover between the
optical centering device and the focusing knob.
? Fix the sheet of paper with the cross on it and mark the fallen point of the center
mark each time when the instrument turns 90º, shown as the illustration: point A, B,
C, D
? Line up points on the cross AC and BD to get the point of their intersection O.
? Regulate the four adjusting screws on the optical plummet with the adjusting pin
to superpose the center mark and point O.
? Other adjustment
Adjust the two leveling screws on the base plate if the screw loosens. The
tightening strength should be suitable.
Adjusting screw
Optical plummet
