Instrument error Description
Telescope camera Telescope camera zero point error, relation
be
tween principal point of telescope camera and
crosshair in telescope in Hz and V - option
If the compensator and the horizontal corrections are activated in the instru-
ment s
ettings, every angle measured in the daily work is corrected automati-
cally. Check whether the tilt correction and the horizontal correction are turned
on.
The results are displayed as errors but used with the opposite sign as correc-
tions when applied to measurements.
The following instrument parts can be adjusted mechanically:
•
Cir
cular level on instrument and tribrach
•
Optical plummet - option on tribrach
•
Allen screws on tripod
To get precise measurements in the daily work, it is important:
•
To check and adjus
t the instrument from time to time.
•
To take high precision measurements during the check and adjust proce-
dures.
•
To measure targets in two faces. Some of the instrument errors are elimi-
nated by averaging the angles from both faces.
During the manufacturing process, the instrument errors are carefully deter-
mined and se
t to zero. As mentioned above, these errors can change and it is
highly recommended to redetermine them in the following situations:
•
Bef
ore the first use
•
Before every high precision survey
•
After rough or long transportation
•
After long working periods
•
After long storage periods
•
If the temperature difference between current environment and the tem-
perature at the last calibration is more than 20°C
Before determining the instrument errors, the instrument has to
be le
velled using the electronic level.
The tribrach, the tripod and the underground should be stable
and secure from vibrations or other disturbances.
The instrument should be protected from direct sunlight to
avoid thermal warming
.
It is also recommended to avoid strong heat shimmer and air
turbulence. The best conditions are early in the morning or with
overcast sky.
Before starting to work, the instrument has to become acclimatised to the
ambient t
emperature. Approximately two minutes per °C of temperature differ-
ence from storage to working environment, but at least 15 min, should be
taken into account.
Mechanical Adjust-
men
t
Precise Measure-
ments
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Settings - TS instrument 263
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