SOIL MOISTURE SENSOR

摘要

A soil moisture sensor which includes a processor to derive soil moisture values and a memory store associated with said processor to store measured values on a periodic basis, wherein the processor scales the stored moisture values to establish a moisture range for the sensor that can be used to calibrate each new reading. The sensor includes a capacitive sensor. In one embodiment the processor measures the capacitance at a single frequency and also measures the phase and amplitude to derive measures of soil impedance due to moisture content and conductivity. In another embodiment the soil sensor capacitor is part of a resonant circuit and the resonant frequency of the circuit is measured as an indication of soil moisture. The sensor is constructed on a single substrate, which also functions as its own insertion stake into the soil.