Determination of overall self-heating of automatic weather stations

Measurements of temperature are a critical part of meteorology and climate studies and the knowledge of used sensor’s key parameters that affect the resulting measured temperature values is of high importance. This paper focuses on the platinum resistance sensors used within automatic weather stations (AWS), which form a basic unit of the meteorological and hydrological services. Self-heating of the these thermometers are the subject of this study that originates not only from the temperature sensor itself, but also from the additional electrical components housed together with these sensors. The purpose of this study and the conducted measurements is to show the temperature change in the close vicinity of the sensors over a time period of more than 66 hours with an electric current and voltage supply recommended by the sensor manufacturers. Furthermore, the temperature change after increasing the voltage supply levels up to 80% of the maximum voltage recommended by the respected manufacturer is presented as well. In the presented study, the measured difference from the initial measured temperature can be high as +0.32°C when elevated voltage levels are used.