ABSTRACT
The author developed a cheap and simple sensor for measurement of soil moisture using a voltage control element transistor (MOSFET). The soil moisture sensor consists of multi-MOSFETs, carbon electrodes, plastic rod, PVC pipe, and cloth for cover. The moisture sensor can be installed into a hole made by portable cone rod in arbitrary depth of the slope. Voltage of the sensor is measured and the value is converted to soil moisture. One of MOSFET detects a submerged condition of the soil. The moisture sensor is applied at a site of the slope and its applicability is discussed based on the field observation. From the result, it is indicated that the simple sensor using MOSFET are useful for not only the measurement of soil moisture but also detection of submerged condition of the ground.
