Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Lumped type parameters
Reexamination Certificate
2006-10-31
2006-10-31
Deb, Anjan (Department: 2858)
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Lumped type parameters
C324S658000, C324S686000, C324S689000
Reexamination Certificate
active
07129713
ABSTRACT:
A moisture sensing apparatus includes an oscillator for supplying an AC signal to a driven ring of a sensor having a pad inside the ring, and a ground plate around the ring. An amplifier forms part of a temperature-compensated, precision rectifier, and is connected to the pad. A first diode connected to the output of the amplifier in a feedback loop of the amplifier, where the amplifier nullifies temperature variation effects upon the diode, and supplies a rectified signal which is a function of moisture content of material in contact with the sensor. A second diodes is connected between the amplifier output and other input of the amplifier. The sensor has a rounded configuration to avoid electrostatic field fringing effects, and a passive impedance with both resistive and capacitive members is connected in parallel with the sensor to provide a functional baseline for the rectified signal.
REFERENCES:
patent: 3771548 (1973-11-01), Rauchwerger
patent: 4259632 (1981-03-01), Ahtiainen
patent: 4620141 (1986-10-01), McCumber et al.
patent: 4823600 (1989-04-01), Biegel et al.
patent: 4845421 (1989-07-01), Howarth et al.
patent: 4966158 (1990-10-01), Honma et al.
patent: 5479104 (1995-12-01), Cambell
patent: 5486815 (1996-01-01), Wagner
patent: 5859536 (1999-01-01), Stockton
patent: 2003/0169054 (2003-09-01), Rynhart et al.
Deb Anjan
Delmhorst Instrument Co.
Kramskaya Marina
Notaro & Michalos P.C.
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