TEST AND INSPECTION - Continued
Azimuth Correction Inspection - Continued
After each elevation setting, recenter bubble in elevation level vial.
When M137/M137A2/M137A3 telescope is aligned on target, final movement of
azimuth knob should be in a clockwise direction.
1 fc 4 7 9
Look through eyeshield (13) of M137 telescope (1) and align M137/M137A2/M137A3 telescope reticle
line on wall target.
The variance in readings is dependent upon which way the 88.9 mils is applied to the
fixture. The 27 ± 0.3 mils would be subtracted from the 4800-mil reading.
Azimuth counter (3) should read 4837 ± 0.3 mils or 4773 ± 0.3 mils.
Repeat steps 5 through 10 using elevations, cant angles, azimuth corrections, and tolerances in Table
Repeat steps 5 through 10, setting cant in opposite direction.
If azimuth counter readings cannot be obtained, check to ensure proper maintenance
procedures were followed when the M171/M171A1 mount was reassembled. If
azimuth correction readings are still unobtainable, there is a possibility of
excessively worn or bent depot parts. Return the M171/M171A1 mount to depot