Calibration of Capacitive Soil Moisture Sensor (SKU:SEN0193)

The new model of a soil moisture sensor is capacitance type sensor which designed from two parallel-plates, in which, soil being measured is located between both electrodes and act as a dielectric material of the capacitor. The sensor model is claimed with a number of advantages especially to solve the problem on the application of conductance type sensors. SKU:SEN0193 is one of a low cost soil moisture sensor which is available on the commercial market. Before applied, it is necessary to know the performance and characteristic of the sensor for local soil application. The purpose of this research is to calibrate the soil moisture sensor for soil humidity measurement. For this, the sensor coupled with such signal conditioning circuit is connected to an Arduino microcontroller and LCD for data acquisition system. The sensor responses to varied moisture of soil samples are compared to the gravimetric methods. In this research, the sensor is calibrated for sandy loam soil texture obtained from Bangka Regency. The result showed that soil moisture content readings by SKU:SEN0193 is not affected by different volume of soil and soil temperature, but is little affected by ambient environmental temperature conditions. There is direct relationship between the soil moisture content (y) and the sensor response (x), sensor performs well so it can be used to measure the moisture content of sandy clay soil sample.