Topcon AT-G4 User Manual

(5) Collimate both scales once more, on a horizontal line of
sight, and read the number on the scales.
If
the readings on both scales are identical, there will be
no need for adjustme nt .
If the reading are different, however, adjustme nt is re-
quired, in the following manner.
(6) Sight the farther scale and shift the horizontal cross-
hair line up or down, as required, until the line is coin -
cided to the same reading as that of the nearer scale,
with the adjustment screws which are exposed when
the eyepiece cover is unscrew ed.
First, loosen the adjustment screw, on the side to which
the horizontal cross-hair line has shifted. Then, tighten
the adjustment screw, on the opposite side to which it
must be moved; by an equal amount.
When making this adjustment, do not loosen the screw
too much at one time but make the adjustme nt as slight
as permissible, and try to keep the tensions of the
screws same at all times, by revolving the screws by
equal amounts. Revolve counterclockwise to loosen
and clockwise to tighten .
(7)
Upon completing the adjustment, check once more to
17
see whether the same numbers are observed on the
scales when checked in the above manner. If not, repeat
the adjustment once more.
Adjustment screw
18

Topcon AT-G4 Specifications

General

Brand	Topcon
Model	AT-G4
Category	Measuring Instruments
Language	English