Vaisala FD12P - Manual (Page 87)

Chapter 4 _________________________________________________________________ Operation
VAISALA ________________________________________________________________________ 87
Warning text Description
CONNECTED
TS SENSOR ERROR The DTS14B measurement is off limits.
DRD12 ERROR The DRD12 analog signal is close to zero.
LUMINANCE SENSOR
ERROR
The LM11 signal is zero (not checked if the BLSC
is negative).
TE SENSOR ERROR Box temperature sensor TE measurement is off
limits.
VISIBILITY NOT
CALIBRATED The visibility calibration coefficient has not been
changed from the default value.
CAL Command
The CAL command is used to calibrate the visibility measurement.
The calibration is done by using opaque glass plates with known
scatter properties.
The command type is the following:
CAL Calibrator_signal_value
↵ ↵↵ ↵
Type, for example, the following:
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).
Refer to section Calibration on page 119 for instructions.
TCAL Command
The TCAL command is used to calibrate the sensor crossarm
temperature (TS) measurement. Only 0 °C temperature is important in
its accuracy because it is used in the identification of freezing rain.
When you type
TCAL
↵ ↵↵ ↵
the command displays the current scaling factors.
Without a parameter, the command displays the current scaling factors
and current TS.
When you type
TCAL TS
↵ ↵↵ ↵