Figure 2-14. Verticle collimation error, adjustment

TM5-6675-296-14

k. Vertical Collimation Error. Refer to figure

2-14 and adjust the theodolite vertical collimation

error.

SIGHT A WELL DEFINED OBJECT WITH THE

STEP 1.

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.

REVERSE THE TELESCOPE POSITION AND

STEP 2.

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 4.

REDUCED BY 6,400 MILS, IS TWICE THE

COLLIMATION ERROR. COMPUTE THE

ZENITH DISTANCE AND SET THE MICROM-

ETER SCALE AT THE CORRECT READING.

MAKE THE COINCIDENCE OF THE

STEP 4.

GRADUATION LINES.

COINCIDE THE COLLIMATION LEVEL

STEP 5.

BUBBLE BY LOOSENING ONE ADJUSTING

SCREW AND TIGHTENING THE OTHER

ADJUSTING SCREW BY AN EQUAL DEGREE.

TS 6675-296-14/2-14

Figure 2-14. Verticle collimation error, adjustment