A kind of humidity sensor based on capacitor may include the container that sleeve has internal cavities, which has soil or other materials insertion cavity, and a pair of of annular conductive band forms capacitor around the external of described sleeve pipe, and provides rate-adaptive pacemaker. It is connected to fixed inductor, around the ring of the circumferential registration of casing to form the oscillator with variable frequency output. Sensor can be calibrated, and from said frequencies output for multiple substances, the volumetric(al) moisture content for measuring saturation is material, determine that volumetric(al) moisture content at least one fitting constant equation is the function and multiple cooperation constants of frequency.
