Optical moisture sensor and method of making the same

Details Optical moisture sensor and method of making the same Optical moisture sensor and method of making the same

2007-07-24

2007-07-24

Lee, John R. (Department: 2878)

Radiant energy

Photocells; circuits and apparatus

Optical or pre-photocell system

C250S573000, C356S128000, C340S603000

Reexamination Certificate

active

11214101

ABSTRACT:
A soil moisture sensor uses a non-collimated light source and a photosensor, respectively, mounted at the foci of a transparent ellipsoidal plastic body. The dimensions of the body are such that emitted light rays are internally reflected toward the photosensor at the surface of the ellipsoid if the surface is dry, but refracted outwardly of the body when the surface is wet. The amount of light reflected onto the photosensor is thus a measure of the amount of moisture at the surface of the sensor. Direct illumination of the photosensor by the light source is prevented either by interposing opaque electronic components between them on a circuit board, or by taking advantage of light source characteristics to minimize the amount of transmitted light. If a circuit board is used, it is completely encapsulated against moisture penetration by fixing it in a carrier and molding the body around and onto the carrier to form a monolithic unit with the carrier and circuit board.

REFERENCES:
patent: 4274705 (1981-06-01), Miller
patent: 4306805 (1981-12-01), Arrington
patent: 4422714 (1983-12-01), Benoit et al.
patent: 4803470 (1989-02-01), Fineman
patent: 4974552 (1990-12-01), Sickafus
patent: 5442435 (1995-08-01), Cooper et al.
patent: 6690452 (2004-02-01), Wilks, Jr.
patent: 6855947 (2005-02-01), Graves et al.
patent: 7189960 (2007-03-01), Zimmerman

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