Nikon NPL-322, Instruction Manual

Page: 159 / 197

Total Station NPL-322 Instruction Manual 145
Checking and Adjustment 6
When the observation on F2 is completed, four
parameters are displayed.
3. Do one of the following:
–
To return to the first observation screen,
press
[ESC]
or the
Redo
softkey.
–
To set parameters on the instrument, press
[ENT]
or the
OK
softkey.
Checking the Instrument Constant
The instrument constant is a numerical value used to automatically correct for the
displacement between the mechanical and electrical centers when measuring
distances. The instrument constant is set by the manufacturer before the instrument is
shipped. However, to ensure the highest operational accuracy, we recommend that
you check the instrument constant several times a year.
To check the instrument constant, you can either compare a correctly measured base
line with the distance measured by the EDM, or follow the procedure below.
To check the instrument constant:
1. Set up the instrument at Point P, in as flat an area as possible.
2. Set up a reflector prism at Point Q, 100 m away from Point P. Make sure that
you take the prism constant into account.
3. Measure the distance between Point P and Point Q (PQ).
If ACV, ACH,Tilt is out of range, OVER appears. Press any key to return to the
first observation screen.
About 100 m
P Q
P R Q