3620677 is referenced by 79 patents and cites 24 patents.

1. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, indicating means on said indicating device, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein.

Indicating device
Application Number
Publication Number
Application Date
December 18, 1961
Publication Date
November 16, 1971
Ayers Morison
Harness Dickey & Pierce
Miles Laboratories
G01n 29/02
G01N 30/60
G01N 30/92
G01N 30/00
G01K 03/04
G01K 03/00
B01D 15/08
G01N 33/02
G01N 31/22
G01N 13/02
G01N 11/00
G01N 33/04
G01N 13/00
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