Chapter 6 ______________________________________________________________ Maintenance
VAISALA ______________________________________________________________________ 195
5.
Clean the LT31 receiver and transmitter windows.
The LT31 system runs a permanent window contamination measurement.
NOTE
After a window contamination warning, only the windows need to be
cleaned.
NOTE
After window cleaning, run a visibility calibration for the
transmissometer; see section Visibility Calibration on page 238.
Cleaning PWD Forward Scatter Sensor
The structure of the PWD forward scatter sensor is explained in Figure
112 below.
1
4
6
6
5
3
2
0401-121
Figure 112 PWD Hardware Structure
The following numbers refer to Figure 112 above:
1 = Transmitter
2 = Controller/Receiver
3 = Vaisala
RAINCAP
®
Rain Sensor
4 = Pt-100 temperature sensor tube
5 = Mounting
clamp
6 = Hood heaters (optional)
Cleaning Lenses and Hoods
The PWD Forward Scatter Sensor lenses need to be cleaned occasionally,
either due to a contamination warning or during the periodic
maintenance. In this frame, the inner surface of the weather protection
hoods should be cleaned as well.