Figure 3-13. Vertical collimation error, adjustment.

TM5-6675-296-14

STEP 1.

SIGHT A WELL DEFINED OBJECT WITH THE

HORIZONTAL CROSSLINE. COINCIDE THE

COLLIMATION LEVEL BUBBLE BY TURNING

COLLIMATION SLOW-MOTION SCREW. MAKE

THE COINCIDENCE OF THE GRADUATION

LINES AND RECORD THE SCALE READINGS.

STEP 2.

REVERSE THE TELESCOPE POSITION AND

SIGHT THE OBJECT. COINCIDE THE

COLLIMATION LEVEL BUBBLE, MAKE THE

COINCIDENCE OF THE GRADUATION LINES

AND RECORD THE SCALE READINGS.

THE TOTAL OF THE TWO READINGS,

STEP 3.

REDUCED BY 6,400 MILS, IS TWICE THE

COLLIMATION ERROR. COMPUTE THE

ZENITH DISTANCE AND SET THE MICRO-

METER SCALE AT THE CORRECT READING.

STEP 4.

MAKE THE COINCIDENCE OF THE

GRADUATION LINES.

STEP 5.

COINCIDE THE COLLIMATION LEVEL

BUBBLE BY LOOSENINGS ONE ADJUSTING

SCREW AND TIGHTENIN6 THE OTHER

ADJUSTING SCREW BY AN EQUAL DEGREE.

TS 6675-296-14/2-13

Figure 3-13. Vertical collimation error, adjustment.