4-3
4
CHECKING AND ADJUS
TMENT
4-4 Zero Point Errors of Vertical Scale
and Horizontal Angle Corrections
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. For the Vertical angle
“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. When your
instrument is out of tolerance, perform the Calibration program and
adjust it before starting your field work.
Summary of Contents for DTM-330
Page 1: ...Electronic Total Stations Model DTM 350 Model DTM 330 Instruction Manual ...
Page 11: ...1 NOMENCLATURE ...
Page 157: ...4 8 4 CHECKING AND ADJUSTMENT ...
Page 190: ......
