Novel soil-moisture-sensors applying thermal characteristics of soil and water

Novel soil-moisture-sensors applying thermal characteristics of soil and water are presented for agriculture use and nature conservation use. These sensors have high sensitivity in low moisture concentrations, small ion effects and are cheap in price. Two types of soil-moisture-sensor applying thermal characteristics of soil and water are presented in this paper. In the first sensor, a phenomenon of heat conduction in soil is applied for estimation of soil moisture, In the second sensor, a phenomenon of heat radiation through soil is applied, These sensors consist of small heater, small aluminum plate, electric thermal sensor and its controller.