Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
Rain Gauge
21
VAN WALT
Monitoring your needs
•
Fill a reservoir with a lockable opening at the bottom with 1000 cm3 water and attach it above
the rain gauge.The amount of water is most accurately determined by measuring the weight
of the reservoir before as well as after filling it with water.
• Let the reservoir slowly drip into the tipping bucket until empty. The emptying of the reservoir
should take at least one hour. Use the datalogger to record the number of contacts. The
number of contacts should roughly be 98, whereby the actual number of contacts determines
the calibration factor.
Determine the calibration factor according to the following table:
A calibration factor between 0.197 and 0.204 is considered acceptable. If the calibration factor
falls outside these parameters, the static and dynamic calibration should be performed again.
0 To achieve optimal measuring accuracy, the Range setting of the datalogger can be adjusted
according to the following formula (see chapter 3.1, “Settings,” to change the Range setting):
R = (0.2 / C.F.) * 100
Where:
R
=
the new Range setting
C.F. =
the (determined) calibration factor
