Cleaning Raincap; Calibration - Vaisala PWD22 User Manual

Chapter 6_______________________________________________________________ Maintenance
NOTE
NOTE

Calibration

VAISALA ________________________________________________________________________ 91
4. After the optical surfaces are properly cleaned, give the CLEAN
command.
It is not necessary to give the CLEAN command after every cleaning.
Alternatively choose the STA command and check that the
Backscatter CHANGE value of both the receiver and the transmitter
is close to zero (set to zero by the previous CLEAN command).

Cleaning RAINCAP


Vaisala RAINCAP Rain Sensor should be cleaned every six months
or more often depending on the conditions.
The measuring principle does not allow for proper ESD protection of
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the RAINCAP electronics, so you must follow the following
instructions:
- Ground your hand first by touching grounded metallic parts of the
installation to remove excessive static charges from your body.
- Clean the RAINCAP
cloth moistened with mild detergent. Be careful not to scratch the
surface.
- Check that the detector is free of ice and snow deposits.
PWD22 has been calibrated at the factory. Normally, PWD22 needs
no recalibration as long as the circuit boards are not changed, or there
is no call for warnings and alarms. The circuit boards need no
hardware calibration.
A periodic check every 6 months is recommended. The user checks
the visibility calibration using the PWA11 calibration kit. If the check
shows less than ±5 % change, recalibration is not recommended,
because the change is within the repeatability of the calibration
procedure.
If any mechanical damage changes or weakens the optical
measurement path, that is, either the receiver or the transmitter, or the
crossarm supporting them, PWD22 must be replaced. If the receiver
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rain detector carefully with a soft, lint-free