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US 4,358,731 AGranted
Apparatus and method for moisture measurement
AssigneePhilip Morris Incorporated
InventorDonald H. Steinbrecher
Life of this patent
Estimating the term…
Abstract
A practice for moisture measurement wherein a transmission means is utilized in conjunction with a circuit means connected in shunt with the transmission means and adapted to receive a material to be tested such that the driving point impedance of the circuit means is dependent upon the moisture content of the material.
Claims13
Apparatus for use in determining the moisture content of a material comprising:
- transmission means;
- circuit means connected in shunt with said transmission means and adapted to receive said material such that the driving point impedance of said circuit means is dependent on the moisture content of said material,
- a variable frequency oscillator connected to the input of said transmission means;
- means for adjusting said oscillator so that it generates energy at a frequency equal to a frequency at which said driving point impedance is at a minimum;
- and means for monitoring the output of said transmission means.
2 more elements
A method of measuring the moisture content of a material comprising:
- providing a transmission means;
- providing a circuit means in shunt with said transmission means;
- applying energy to said transmission means at a frequency at which said driving point impedance is at a minimum;
- monitoring the output level of said transmission means;
- applying said material to said circuit means such that the driving point impedance of said circuit means is dependent on the moisture content of said material;
- varying the frequency of said energy until said driving point impedance is returned to said minimum;
- and
- varying the attenuation of said transmission means subsequent to applying said material to restore the output of said transmission means to said monitored level, the attenuation variation being proportioned to and therefore indicative of the moisture content of said material.
5 more elements
Dependencies are inferred from the claim text.