Temperature Stability of the Sky Quality Meter

The stability of radiance measurements taken by the Sky Quality Meter (SQM) was tested under rapidly changing temperature conditions during exposure to a stable light field in the laboratory. The reported radiance was found to be negatively correlated with temperature, but remained within 7% of the initial reported radiance over a temperature range of -15 degrees C to 35 degrees C, and during temperature changes of -33 degrees C/h and +70 degrees C/h. This is smaller than the manufacturer's quoted unit-to-unit systematic uncertainty of 10%, indicating that the temperature compensation of the SQM is adequate under expected outdoor operating conditions.