Instrument Straighten
In order to hold level during an alignment an instrument must first be straightened so that its level measurement frame is aligned with the working gravity frame. This is accomplished by using the Straighten commands.
Align Instrument Z Axis with Working Frame. This command is only used with Total Stations or other instruments with an active compensator or stations that have had a level compensation performed outside of SA. In this scenario the base frame, or origin of the tracker model is already aligned with the gravity measurements from this instrument and all that is needed is to straighten the instrument model within the job file. Once complete its possible to verify the Straighten operation by checking the instrument's transform directly (through the instrument properties). The Rx and Ry tilt with regard to the working frame should read exactly zero when complete.
Align Level Frame Z-axis with Working Frame. This second option is used for instruments that measure level within SA and record a level measurement frame. This command offers the opportunity to select the level measurement in order to alignment the instrument. It will orient the instrument in the job file such that the selected level frame is aligned with the working frame, rather than the instruments base frame. This is the typical option for laser trackers.