Hukseflux’s HFP01 has replaced the HFT3 as our heat-flux plate for applications that do not require self-calibration. The HFP01 outputs a voltage signal that is proportional to heat flux. Heat-flux plates typically measure heat flux of soil as part of a larger energy-balance measurement system. In this application, two or more HFP01 sensors are buried at a depth of 8 cm, and located at least 1 m from each other.