4.1 Horizontal circle reading
Slacken horizontal and vertical clamps (26,15), turn the alidade. Point telescope to
target means of optical sight (5) tighten clamps. Set cross hairs close to target by
turning horizontal and vertical drives (22,23). Use double hair straddles the target if
the target is small enough, otherwise use single vertical hair splits the taget.
Turn the change-over knob to its stop, so that the white line on the knob is
horizontal. Open and turn the mirrors towards the light so that the field of view of
reading microscope is evenly illuminated.
The eyepiece of the reading microscope is turned until the circle graduation lines are
in focus. The cover is then opened and the circle drive (14) ispressed and turned
until the required reading appears. The circle drive is pulled out. The cover is now
To Next Page
Loading...
