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:
Dec. 24, 1991
Filed:
Jul. 18, 1990
Lars Stormbom, Vantaa, FI;
Vaisala Oy, Helsinki, FI;
Abstract
The invention concerns a capacitive humidity sensor (6) capable of being connected to a measurement device of dielectric factor and a method for producing the sensor. The sensor comprises a dielectric layer (3), whose dielectric factor changes according to the moisture content absorbed in the layer, and at least two galvanically isolated conductive layers (2,1) enclosing the dielectric layer (3), where one of the conductive layers (2) of the capacitor construction is provided with a random pattern of clefts (7), which allow an immediate communication of ambient air with the dielectric layer (3). According to the invention, the dielectric layer (3) has a solid structure without cracks corresponding to the clefts (7) of the conductive layer (2). The construction according to the invention offers a reduction of the capillary effect and associated hysteresis up to a complete elimination of the effect in some embodiments of the invention.