Northwest NCL-22 User Manual - page 7
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4.4 Horizontal Circle and Vernier Reading
Your instrument is equipped with a easy to read horizontal circle for simple angle turning. You can find the circle
and index line above the circle-positioning ring. The horizontal ring is easy to use. It is graduated every single
degree and is numbered every 10 degrees.
Use the plumb bob provided and set up the instrument directly above the surveying point. Sight the objective and
set the horizontal circle to 0 degrees by turning the horizontal circle positioning knob. Turn the telescope to view
the second observation of your angle. Use the fine motion tangent screw can to bring crosshairs precisely on line
with the tangent objective. Using the index line take the angle reading. The index line can be used for reading the
circle in increments finer than single degrees. This process is for estimation but the average user can position the
index line for finer readings.
4.5
Compensator Lock
All Northwest Instrument's NCL series Automatic Levels are equipped with a locking mechanism that protects the
compensator against rough handling, transporting and any time the instrument is in its case.
The compensator lock can also be used as a compensator check. Push and release the lock button and jiggle the
compensator. It should return to the exact horizontal position observed before you pushed the lock button. This
will assure you that the compensator is working properly before you start a job, or after your instrument has been
knocked out of level.
NOTE: This should not be used as a calibration test; regular inspection and
calibration by a qualified technician is recommended.