A Low-Cost Microwave Moisture Sensor

摘要

A low-cost microwave moisture sensor for granular materials operating at a single frequency of 5.8 GHz has been built and tested. The sensor principle is based on measurement of the two components of the relative complex permittivity. From these measurements, a density- and material-independent calibration function is calculated. The linear correlation between the calibration function and moisture provides moisture content in different materials independent of bulk density.