Cleaning Raincap; Calibration; Visibility Calibration - Vaisala PWD22/52 User Manual

Vaisala present weather detector
Table of Contents

Advertisement

Chapter 6 ______________________________________________________________ Maintenance
NOTE

Calibration

VAISALA _______________________________________________________________________ 83

Cleaning RAINCAP

Vaisala RAINCAP
more often depending on the conditions.
The measuring principle does not allow for proper ESD protection of 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.
PWD22/52 has been calibrated at the factory. Normally, PWD22/52
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 cross arm
supporting them, PWD22/52 must be replaced. If the receiver unit
(PWC22/52) or transmitter unit (PWT11) is replaced, both visibility and
contamination measurements need recalibration.

Visibility Calibration

The calibration is checked and adjusted with the PWA11 calibration kit.
The kit consists of a blocking plate and two opaque glass plates with
known scatter properties. The ZERO , CHEC , and CAL commands are
used in the procedure. The calibration procedure checks two points; zero
scatter signal and a very high scatter signal. The zero signal is obtained
using a blocking plate and the high signal using opaque glass plates.
®
Rain Sensor should be cleaned every six months or
®
rain detector carefully with a soft, lint-free

Advertisement

Table of Contents
loading

This manual is also suitable for:

Pwd22Pwd52

Table of Contents