Before beginning work, ensure that the switched-on instrument mounted on
the tribrach has acclimatized to the surrounding ambient temperature. Allow
at least 20 minutes for this process, or approximately 2 minutes per °C of
temperature difference between the storage environment and the working
environment.
Precise manual aiming procedures are the base for a fitting determination of
the instrument error corrections. Take the time to aim accurately and measure
with highest precision. For consistent Check & Adjust results on job sites with several instruments, the procedures should be performed by the same operator on all instruments.
Even after adjustment of the ATR, the crosshairs may not be positioned exactly
on the centre of the prism after an ATR measurement has been completed. This outcome is a normal effect. To speed up the ATR measurement, the telescope is normally not positioned exactly on the centre of the prism. These small deviations ATR offsets, are calculated individually for each measurement and corrected electronically. This means that the horizontal and vertical angles
are corrected twice: first by the determined ATR errors for Hz and V, and then
by the individual small deviations of the current aiming.
Next step
