TM 9-1240-400-34&P
5-19. FINAL INSPECTION INSTRUCTIONS (CONT).
CHECKING M137 TELESCOPE MOUNT ACCURACY
1 Place M137 telescope mount (1) on adapter (2) and secure with four capscrews (3). Turn cross-level knob (4) and
elevation knob (5) and center the bubble in each level vial (6) and (7). The elevation and correction counters (8) should
be at zero.
2 Suspend a plumbline 30 feet (9 m) in front of the panoramic telescope in line with the test target.
3 With M137 telescope mount and cross level and elevation test fixture leveled in both directions, place M115 panoramic
telescope (9) on top surface of M137 telescope mount (1).
4 Aline the vertical line of the telescope with the plumbline and vertical line of the test target.
5 Rotate elevation knob (5) of M137 telescope mount to its extreme clockwise position, simultaneously rotating the
elevation fixture wheel (10) keeping the line of sight on target. Rotate elevation knob (5) of M137 telescope mount to its
extreme counterclockwise position and repeat steps 2 thru 4. The line of sight, when viewing through the M115
panoramic telescope (9), shall not deviate from the plumbline by more than 0.5 mil as read on test target at any point of
the elevation or depression travel. Adjust cross level vial (7) to meet above standard.
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