The Effects of Dome Temperature Gradients on the Accuracy of the Eppley Precision Infrared Radiometer

Measurements from the Eppley Precision Infrared Radiometer (PIR) can be corrected for dome heating when the dome temperature is known. Traditionally, a single temperature sensor is installed at the base of the PIR dome and is used for the correction. In the correction it is assumed that the entire dome is at the same temperature as the dome temperature sensor. Temperature gradients across the dome can be present especially under clear sky conditions and this can result in errors when applying the dome temperature correction.

This poster will examine results using a specially designed PIR dome with three temperature sensors installed by the manufacturer. The magnitude of the dome temperature gradients will be examined and the effects of the gradients on the dome correction will be discussed. The effects of sensor ventilation using a standard Eppley ventilator will also be discussed and the effects on the dome temperature gradient will be shown.