The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1987
Filed:
Jan. 23, 1984
Gary R Weihe, Fremont, CA (US);
Roger D Lion, Menlo Park, CA (US);
Raychem Corporation, Menlo Park, CA (US);
Abstract
An apparatus for measuring the moisture content of soil includes a chamber having a water-swellable material in the chamber, the chamber being sized so that the water-swellable material can swell to its fully swollen state, with the external resistance, if any, against the swelling being substantially constant. The device includes a device for transmitting water to the water-swellable material so that it is in equilibrium with the environment. A sensor responsive to the volume of the water-swellable material is provided to indicate the water content of the environment exterior of the apparatus. The preferred sensor is a magnet moveable by the water-swellable material and a Hall effect sensing device.