Vaisala FD12P - Manual (Page 123)

Chapter 6 _______________________________________________________________Maintenance
VAISALA _______________________________________________________________________ 123
The following numbers refer to Figure 31 on page 122:
1 = Crossarm
2 = Grooves
3 = M8 x 40 DIN912, 2 pieces
4 = Calibrator clamp
5 = Center of crossarm
6 = Tie rod
7 = Pole mast
8 = Label
9 = Left opaque glass plate
10 = Right opaque glass plate
Calibration Procedure
If calibration is needed according to the calibration check (see section
Calibration Check Procedure on page 120), follow the instructions
below. The opaque glass plates are installed on the crossarm as
described in the previous paragraph.
To perform calibration according to the calibration check, do the
following:
1. Give the
CAL calibrator signal value
↵ ↵↵ ↵ command, for
example,
CAL 985
.
The calibrator signal value is printed on the labels of the glass
plates. Typically the signal is close to 1000 Hz. The FD12P
calculates a new scaling factor and stores it in the non-volatile
memory (EEPROM).
2. Type
CHEC
to learn the new scaling factor that should be equal to
the calibrator signal value. If the difference between the new
scaling factor and the factory calibrated one is more than 20 %,
the CAL command will be ignored. Check the FD12P and the
calibrator for hardware or mechanical errors.
If optical units FDT12B or FDR12 have been replaced, the new
scaling factor might change more than 20 % from the original
scaling factor value and thus, the CAL command is ignored. In
this case, use the FCAL command (factory calibration) during
the calibration procedure.