초록 ▼

A microwave grain monitor determines grain density and moisture content without measuring the phase shift of the measurement signal in passing through the grain. A set of grain coefficients is determined and stored in a non-volatile memory. A microwave measurement signal is transmitted through the g

A microwave grain monitor determines grain density and moisture content without measuring the phase shift of the measurement signal in passing through the grain. A set of grain coefficients is determined and stored in a non-volatile memory. A microwave measurement signal is transmitted through the grain and the ambient temperature is sensed. The grain density and moisture content are determined from the attenuation of the measurement signal in passing through the grain, the sensed temperature and the set of grain coefficients.

대표청구항 ▼

[ We claim:] [1.] A grain monitor comprising:a transmit antenna and a receive antenna disposed on opposite sides of a sensing region;a grain feed tube extending through said sensing region;an auger for pushing grain upwardly against gravity through said feed tube;a temperature sensor for sensing the

[ We claim:] [1.] A grain monitor comprising:a transmit antenna and a receive antenna disposed on opposite sides of a sensing region;a grain feed tube extending through said sensing region;an auger for pushing grain upwardly against gravity through said feed tube;a temperature sensor for sensing the temperature of the grain and producing an output signal;a microwave signal source for applying a microwave measurement signal to said transmit antenna for transmission through said sensing region;detector means including a diode detector connected to said receive antenna for detecting the magnitude of the measurement signal after it has passed through the sensing region; and,a microprocessor means connected to said temperature sensor and said detector means, said microprocessor means including,a memory for storing a grain coefficient table, the grain coefficient table having therein at least one set of grain coefficients relating to grain of the type being pushed through the feed tube,first means for calculating the wet density and dry density of the grain from said grain coefficients, the temperature sensed by said temperature sensor and the magnitude of the measurement signal detected by said detector means; and,second means for calculating the moisture content of the grain from the wet density and the dry density.