Section III: PRINCIPLES OF OPERATION - TM-5-6675-329-13-P0017

TM 5-6675-329-13 & P

Compensator

Working range

+ 15 minutes of arc (1)

Setting accuracy

+ 0.3 seconds of arc (")

Circular Level

Sensitivity per 2 mm

8 minutes of arc, or (1)

Section III: PRINCIPLES OF OPERATION

The principle of operation of the self-leveling Automatic Level NA2-80 is based on a compensating element containing a

prism which establishes a horizontal line of sight by correcting the light path of an unleveled instrument. Beyond the

range of automatic adjustment, the level can be manually adjusted to a centered-bubble condition.

To check the operation of the compensator, a test pushbutton is incorporated in the level. When momentarily pressed,

the pushbutton moves the compensator off-center. A functioning compensator will swing around the level position and

then automatically return to it.

For surveying purposes, an adjustable focus telescope has been made an integral part of the level. The level also

contains a horizontal drive mechanism which allows it to be turned in the horizontal plane.

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