User's Guide ______________________________________________________________________
218 _________________________________________________________________ M210667EN-C
CAUTION
After repair of the measurement unit, fine alignment and calibration
must be carried out to establish normal operational conditions. For
details, see sections Fine Alignment on page 231 and Calibration on
page 232.
10. Re-install the measurement head cover and lock it carefully.
11. Close the interface unit and mount the upper interface unit cover
after finalizing fine alignment and calibration.
Replacing Main Receiver Module LTD112
The LTM212 receiver measurement unit of the LT31 is equipped with
the main receiver module LTD112. In case of a faulty main receiver
module, the measurement unit has to be opened for replacement
purposes.
NOTE
To replace the main receiver module LTD112, the measurement unit has
to be opened. For this reason it is highly recommended to dismount the
complete measurement unit and carry out the replacement work on a
clean workbench in a dry room.
NOTE
If the weather conditions allow, it is possible to replace the main
receiver module on site. In that case, the measurement unit remains
installed on the mast.
To access the receiver measurement unit, the AC power has to be
switched off first and then the measurement head cover has to be
removed.
1.
Remove the upper interface unit cover and open the interface unit
with the provided key.
NOTE
Switch the AC switch off, before you proceed with the next steps. In
case of the optional LTBB111, switch the battery backup switch off as
well. See Figure 40 on page 83.
2.
Loosen the three lock screws at each side of the measurement head
cover and carefully remove the cover from the measurement head.
See Figure 95 on page 140.