Patent ID: 7316198
Filing Date: 2008-01-08
Classification: G01N,Y10S

Abstract:
1. A humidity indicator, comprising at least one humidity-determining face which is provided on a surface of a humidity-determining plate comprising cobalt chloride held in a base paper sheet, so that the cobalt chloride is exposed to the humidity-determining face, whereby humidity is determined by the discoloration of the cobalt chloride on the humidity-determining face, characterized in that said humidity indicator further includes a first film covering the surface of said humidity-determining plate, and a second film covering the back of said humidity-determining plate; a flat air layer is formed at least between the first film and the surface of the humidity-determining plate, so that the entire surface of said humidity-determining face faces to said air layer; a plurality of small holes are formed at distances from one another in said first film to permit the direct communication of said air layer with the atmosphere; said first and second films are formed to protrude from an outer peripheral edge of said humidity-determining plate and bonded at outer peripheral edge portions thereof directly to each other; and said first and second films are bonded in a compression manner to a portion of said humidity-determining plate surrounding a region corresponding to said air layer.