Calibration and applicability of EC-5 sensor

Abstract

Sensors detecting soil volumetric water content by measuring the dielectric constant of the media are be-coming popular in environmental science. Some of them such as EC-5 (Decagon devices Inc.) is convenient due to lower price and smaller size. However, it is still not clear size of region the sensor can detect moisture. In addition, some soils do not obey to the supplier distributed calibra-tion curve between output voltage and volumetric water content of the media. Here, we tried to determine size of active area around the sensor. As well, a new procedure to determine a calibration curve based on soil water retention curve is proposed.