The Pt-100 will not give a good indication of ambient air temperature; at 1000 Watts per square
meter Solar Radiation, and no wind, the instrument temperature will rise approximately 12 degrees
above ambient temperature.
The offsets of both pyranometers and pyrgeometers might be larger than 10 Watts per square
meter if large temperature gradients are forced on the instrument (larger than 5 K/hr). This happens
for example when rain hits the instrument. The occurrence of this can be detected using the Pt-100
readout. It can be used as a tool for quality assurance of your data.