Vaisala PWD22/52 - Clrs

Chapter 5 ________________________________________________________________ Operation
VAISALA _______________________________________________________________________ 61
where
Heavy snow limit = The maximum visibility (m) of two-minute
average in heavy snow.
Light snow limit = The minimum visibility (m) of two-minute
average in light snow. If snow is detected
and the two-minute average visibility is
between the above heavy and light limits,
snow intensity is reported as moderate.
DRD scale = The scaling factor for the calculated
intensity of the RAINCAP
®
surface sensor.
A typical value for this parameter is 1.0.
The precipitation measurement can be calibrated by comparing the
PWD22/52 rain amount to measurements made with a suitable reference
rain gauge.
This comparison should be made after a few rain events with 5 mm or
more of total accumulated rain. A new scaling factor can be calculated
using the following formula:
NEWSCALE = OLDSCALE * (REF_AMOUNT / PWD_AMOUNT)
where
OLDSCALE = The old value of rain intensity scale.
REF_AMOUNT = The amount measured with the reference rain
gauge.
PWD_AMOUNT = The corresponding amount measured by
PWD22/52.
CLRS
The CLRS command resets (to 0.00) the precipitation cumulative sums.
This can be done by the host with the following command:
E
C
PW id C
C
R
where
E
C
=
ESC (ASCII character 1B hex.
<
A
K
= ASCII character (06 hex).
C
R
= ASCII character (13 hex.)