User’s Guide ______________________________________________________________________
32 __________________________________________________________________ M211840EN-C
Precipitation Measurement Principle
The transmitter uses Vaisala RAINCAP Sensor 2-technology in
precipitation measurement.
The precipitation sensor comprises of a steel cover and a piezoelectrical
sensor mounted on the bottom surface of the cover.
The precipitation sensor detects the impact of individual raindrops. The
signals from the impact are proportional to the volume of the drops. The
signal of each drop can be converted directly to accumulated rainfall.
An advanced noise filtering technique filters out signals originating
from other sources than raindrops.
The measured parameters are:
-
accumulated rainfall
-
rain current and peak intensity
-
duration of a rain event
Detecting each drop enables the computing of rain amount and intensity
with high resolution.
Precipitation current intensity is internally updated every 10 seconds
and represents the intensity during the one minute period before
requesting/automatic precipitation message sending (for fast reactions
to a rain event, during the first minute of the rain event, the intensity is
calculated over the period rain has lasted in 10-second steps instead of
a fixed period of one minute). Precipitation peak intensity represents the
maximum of the calculated current intensity values since last
precipitation intensity reset.
The sensor can also distinguish hail stones from raindrops. The
measured hail parameters are the cumulative number of hail stones,
current and peak hail intensity and the duration of a hail shower.
WXT536
WXT535
WXT534
WXT533
WXT532
WXT531
X
X
X
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