TM 5-6675-329-13 & P
Section III: OPERATIONAL CHECKS
Operational checks, consisting of instrument leveling and focusing checks, are shown in Table 4-1. Perform the
procedures weekly when the instrument is in regular use. When the instrument is not used regularly, perform the
procedures before each use.
Table 4-1. Instrument Leveling and Focusing Checks
Level the telescope.
Circular level (8, Figure 1-2) bubble remains centered when instrument is rotated through
Set up Tripod Assembly GST-40 so that its legs are stable and firmly planted
on (or in) the ground, in an as near level position as possible.
With Automatic Level NA2-80 mounted on Tripod, turn the horizontal drive
knob(s) to rotate level through 360° in the horizontal plane, while matching
circular level bubble through prism. Bubble should remain centered through
360° of rotation. If not, readjust footscrews(s) at level positions(s) where it
goes off center, and re-rotate level until bubble remains centered throughout
continuous rotation. Press the test pushbutton (7, Figure 1-2) while looking
through the telescope. The telescope image should momentarily move off
center and then come back to the centered position. This assures the level
compensator mechanism is functioning properly.
When instrument is focused reticle crosshairs appear sharp and absolutely black (See
Point instrument to a uniformly lighted surface or a sheet of white paper.
Rotate eyepiece (Figure 1-2, item 6) until above normal indication is obtained.
Image (usually a leveling staff) is sharp and free from parallax with respect to reticle