Figure 2-19. Horizontal collimation error, adjustment.

TM 5-6675-306-14

STEP 1.

SET UP THE THEODOLITE (PAR. 2-2).

STEP 2.

SIGHT A WELL DEFINED OBJECT WITH THE

VERTICAL

CROSSLINE.

MAKE

THE

COINCIDENCE OF THE GRADUATION LINES AND

RECORD THE SCALE READINGS.

STEP 3.

REVERSE THE TELESCOPE POSITION AND

SIGHT THE OBJECT. MAKE THE COINCIDENCE

OF THE GRADUATION LINES AND RECORD THE

SCALE READINGS.

STEP 4.

THE

DIFFERENCE

BETWEEN

THE

TWO

READINGS, REDUCED BY 180 DEGREES IS

TWICE THE COLLIMATION ERROR.

STEP 5.

SET THE MICROMETER SCALE AT ONE-HALF THE

FIGURE COMPUTED BY STEP 4. MAKE

THE

COINCIDENCE OF THE GRADUATION LINES BY

TURNING THE HORIZONTAL SLOW-MOTION

SCREW.

STEP 6.

WITH THE TELESCOPE IN THIS POSITION,

CENTER THE VERTICAL CROSSLINE ON THE

OBJECT AS FOLLOWS:

TO MOVE THE CROSSLINE TO THE RIGHT,

LOOSEN LEFT ADJUSTING SCREW AND TIGHTEN

RIGHT ADJUSTING SCREW BY AN EQUAL

DEGREE.

TO MOVE CROSSLINE TO THE LEFT, LOOSEN

RIGHT ADJUSTING SCREW AND TIGHTEN LEFT

ADJUSTING SCREW BY AN EQUAL DEGREE.

Figure 2-19. Horizontal collimation error, adjustment.

2-30

Index