1-2
1 NOMENCLATURE AND FUNCTIONS
Sighting collimator
Use sighting collimator to aim the GM in the direction of the measurement point. Turn the
instrument until the triangle in the sighting collimator is aligned with the target.
A gun sight is mounted on Face 2 position of the iM-55. Align the telescope to the direction of the
target in such a way that the gun sight is positioned with the target as shown below. Note that you
see the target at a distance from the gun sight.
Horizontal direction: a position where you can see both the target and back sight at the center of
the front sight's slit.
Vertical direction: a position where you can see the tops of the front sight and back sight at the
same height of the target's center.
Instrument height mark
The height of the GM is as follows:
•
192.5 mm (from tribrach mounting surface to this mark)
•
236 mm (from tribrach dish (TR-103R) to this mark)
"Instrument height" is input when setting instrument station data and is the height from the
measuring point (where GM is mounted) to this mark.
Laser-pointer Function
A target can be sighted with a red laser beam in dark locations without the use of the telescope.
Handle
The carrying handle can be removed from the instrument when the prism is located at the zenith
etc.
To remove it, loosen the handle locking screw.
Gun Sight
Target
Front sight
Back sight
Equal intervals
Handle
Handle
locking screw
