Microwave moisture measuring, indicating and control apparatus

A microwave moisture measuring and indicating apparatus for measuring the moisture content of moisture absorping material in an inspection area comprising a microwave transmitter means located to one side of the inspection area for transmitting a microwave monitoring beam of a selected frequency and energy level toward and through the material at the inspection area, a microwave receiver means located to the opposite side of the inspection area for receiving microwaves transmitted through the inspection area and the material located therein, said microwave transmitter means including a concave substantially parabolic reflector facing toward the inspection area and a microwave oscillator means providing a localized source of microwave energy spaced toward the inspection area from said parabolic reflector and located substantially at the focal point of the latter for directing microwave energy toward said parabolic reflector which is thereupon reflected toward the inspection area as a microwave monitoring beam of much larger transverse area than said source, said microwave receiver means including a substantially parabolic receiver reflector similar in size and shape to the reflector of said transmitter means located in the path of said monitoring beam to receive microwave energy after passage through said inspection area and including a microwave detector means located toward said inspection area from said parabolic receiver reflector at substantially the focal point thereof for detecting the microwave energy impinging on said parabolic receiver reflector and reflected thereby to said detector means and producing a detector output signal, signal processing means for amplifying and processing said detector output signal for producing a D-C moisture indicating signal which is directly proportional to the moisture content of the material in said inspection area through which the microwave energy of said beam passed, indicator means responsive to said D-C moisture indicating signal for indicating a quantity which is a function of the moisture content of said material, and each of said microwave transmitter means and microwave receiver means having a layer of microwave absorping material between the respective parabolic reflectors and said inspection zone in the path of the microwave energy forming said monitoring beam.