The internal operating temperature of the UVB, MFR, UVMFR, SPUV, RSS is about 45 C. Why is this?
To eliminate effects of changing ambient air temperature and solar loading, we thermally stabilize the internal optics of our instruments to above ambient temperature, between 38 C and 45 C, depending on the instrument. The exact temperature is not as important as knowing that the temperature is stable and has been stable since the most recent calibration.