Campbell Scientific CNR1 Net Radiometer - Manual (Page 32)

Appendix B. Details about Using the Heater
For decisions about heating one can make the following diagram:
12 VDC, 6 VA available?
Not available
DO NOT HEAT
Available Consider options below
Clock and relay available?
Not Available
DO NOT HEAT
(CSI recommendation)
Available
Heat from 1 hour before the sunset
until 1 hour after the sunset
The maximum allowable power for the heater is 50 VA. In case of snow or
frost one might also consider heating at a higher level than the usual 6 VA.
Heating at 20 VA will melt snow in most cases. 20 VA can be reached at 22
Volts. During high power heating, measurement accuracy cannot be specified.
You are advised to reject measured data readings during this high power
heating.
If lower voltage is available, one might consider heating at a lower power. The
6 VA is designed for extreme conditions. 2 VA is sufficient for moderate
conditions.
Time needed for reaching a stable instrument temperature when heating is used
is about 60 minutes.
B-2