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:
Jan. 02, 1990
Filed:
Dec. 20, 1988
Mitchell Instruments Ltd., Cambridge, GB;
Kabushiki Kaishia Tekune Yohkoh, Tokyo, JP;
Abstract
A hygrometer of the electrical impedance type includes a sensing element (1) having a porous moisture adsorbing layer (3), the electrical properties of which vary with the quantity of water vapour adsorbed on it sandwich between a substrate (2) and a porous conducting electrode (4). The conducting electrode (4) is divided into a number of separate measuring zones (6A, 6 and 6C) by gaps (5). The hygrometer also includes a redundancy system circuit (7) which is connected to each of the separate measuring zones (6A, 6B and 6C) and which only provides a moisture indication when the output from at least two of the zones (6A, 6B and 6C) are in agreement. This arrangement enables failures of the sensing element (1) to be detected and distinguished from a false moisture indication.