US 6,982,562 B2
Multiple frequency grain moisture sensor for combines
Gerald E. Rains, Bettendorf, Iowa (US); James J. Phelan, Bettendorf, Iowa (US); Zachary W. Slavens, Bettendorf, Iowa (US); Andrzej Kozicki, Milan, Ill. (US); and Robert C. Funk, Auburn, Ill. (US)
Assigned to Deere & Company, Moline, Ill. (US)
Filed on Jun. 06, 2005, as Appl. No. 11/145,755.
Application 11/145755 is a division of application No. 10/718147, filed on Nov. 20, 2003, granted, now 6,917,206.
Application 10/718147 is a division of application No. 10/145463, filed on May 14, 2002, granted, now 6,647,653.
Application 10/145463 is a division of application No. 10/003884, filed on Oct. 25, 2001, granted, now 6,686,749.
Prior Publication US 2005/0225334 A1, Oct. 13, 2005
Int. Cl. G01R 27/26 (2006.01)
U.S. Cl. 324—694 5 Claims
OG exemplary drawing
 
1. A grain moisture sensing system comprising:
an excitation signal source for producing an excitation signal;
a sensor cell having a driven plate for applying the excitation signal and a sense plate proximate to and substantially parallel with the driven plate for capacitive measurement across a spacing between the driven plate and the sense plate such that a sense current is produced at the sense plate;
the excitation signal source electrically connected to the driven plate of the sensor cell;
a first synchronous detector adapted for measuring components of the excitation signal, the synchronous detector electrically connected to the excitation source; and
a second synchronous detector adapted for measuring components of the sense current, the second synchronous detector operatively connected to the sense plate.