Abstract: An improved moisture detection apparatus for use in detecting moisture in discrete objects brought seriatim to a sensing zone. The apparatus includes structure for transmitting a beam of microwave energy having a planar wavefront through a portion of the object brought to the sensing zone and utilizing signal processing structure for selectively providing peak detection or averaging integration of the microwave beam signal in providing desired accuracy in the determination of the moisture content of such objects which may vary in uniformity of the moisture content thereof. Microwave absorber material is provided in the signal path between the microwave horns and the object. The invention includes structure for accurately aligning the horns notwithstanding the use of an opaque conveyor for bringing the objects to the sensing zone interposed between the horns.

Abstract: An apparatus and method for providing improved measurement of moisture in a sample cell by use of microwave energy. Improved accuracy and reliability of the moisture determination is obtained by causing solely parallel beam, planar wavefront microwave energy to be passed through the sample in the test cell. The apparatus includes transmitting and receiving antennas and refractor elements (lenses) interposed between the antennas and the sample cell. The antennas, refractor elements, and sample cell may be located within an anechoic chamber. The invention comprehends locating the sample cell in the near field of the transmitting antenna and coordinating the characteristics of the refractor elements with the spacing of the antennas relative to the sample cell.

Abstract: An apparatus and process is disclosed for enabling the measurement of moisture in a sample cell by use of microwave energy. A sample cell of predetermined volume is located within an anechoic chamber and positioned on a weight measuring device to measure the weight of any material in the sample cell. Microwave energy is directed through the material in the sample cell by means of a transmitter and receiver to provide a measurement of the water weight in the sample. A temperature sensor is located to measure the temperature in the cell and the reading is combined with the microwave water weight measurement and the weight of the sample to calculate the percent moisture and the bulk density of the material.