The POGO Pro uses a thermistor that is embedded in the plate of POGO’s integrated sensor that rests on the turf surface. This surface is full of turf leaves and air pockets. As temperature energy is transferred from the canopy to the sensor plate, the thermistor will read that conducted heat. This process can be delayed if the POGO has heated up from the sun to a degree higher than the turf’s temperature. The thermistor is sensitive and reactive to small changes and takes time for the sensor to acclimate to the turf’s temperature once you put it in the ground.
The POGO Pro does NOT measure soil temperature although the temperature at the surface is influenced by the underlying soil temperature.