Vaisala FS11P - Optical Contamination and Blocking Monitoring; Table 29 Warning Messages; Table 30 Indication Messages

User's Guide _______________________________________________________________________
162 __________________________________________________________________ M211107EN-C
SCATTER SIGNAL
SATURATED
There is an obstacle in the measurement
volume that causes excessive scattering.
SIGNAL OFFSET DRIFTED
Offset has drifted more than ±5 LSB from
zero, caused by other disturbing visibility
sensors nearby or other interference
problems.
TEMPERATURE SENSOR
FAILURE
The surface temperature sensor is
disconnected or has failed.
Table 29 Warning Messages
WARNINGS
Reasons
WINDOW CONTAMINATED
Window contamination has increased and
caused the window transmission to drop
below 85%. The contamination
compensation is still reliable.
BATTERY LOW
Backup battery voltage low (<11 VDC),
limited operation time left
LED AGED
LED aged, required electrical driving power
increased, limited operation time left
Table 30 Indication Messages
INDICATIONS
Reasons
WORKING ON BATTERY
AC (mains) off, hood heaters not
operational
+12V OUTPUT
DISCONNECTED
+12 V output on the interface unit is
disconnected due to a short-circuit in the
output line. This has no effect on the
measurement but warning lights or other
options powered by this output will not
work.
HOOD HEATER FAULT
Hood heater not operational. Hood
temperature has increased less than 2 °C
within 5 minutes since the heater was
turned on by the automatic heater control
circuit.
NOTE: If operated only with battery or DC
power, set the hood heater OFF to prevent
this indication.
DEW HEATER FAULT
Dew heater not operational, no current
runs through the heater when it is on
Optical Contamination and Blocking
Monitoring
Optical contamination and blocking of both the transmitter and the
receiver are continuously monitored. The FS11P sensor monitors
contamination and blocking by measuring window contamination and
backscattered signals. The CLEAN command is used to set clean