Zero Point Errors Of Vertical Scale - Nikon DTM-350 Instruction Manual

4-4 Zero Point Errors of Vertical Scale

1) Checking
(1) Set up the instrument on the tripod and complete the leveling
procedure described in [2-5. Leveling] section. (See p.2-9)
(2) On the BMS, with the telescope in its Face1 position, sight a target that
is placed within ±45° from the horizontal plane, and read the vertical
angle (V1).
(3) Rotate the instrument and flip the telescope to its Face2 position, and
take another vertical angle reading (V2) to the target.
(4) For the Vertical angle "Zenith" setting, if the "V1+V2" equals 360°,
then the adjustment is not necessary.
"Horizon", when the "V1 + V2" is 180° or 540°, then the adjustment is
not required either.
Difference in vertical angle reading from 360° (for Zenith), 180° or
540° (for Horizon) , is called the Altitude constant.
instrument is out of tolerance, perform the Calibration program and
adjust it before starting your field work.
and Horizontal Angle Corrections
For the Vertical angle
When your
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