05667303 is referenced by 106 patents and cites 51 patents.

A selectively activated time-temperature integrating device for providing a visually observable indication of cumulative thermal exposure, in which a viscoelastic material migrates into a diffusely light-reflective porous matrix at a rate which varies with temperature to progressively change the light transmissivity of the porous matrix and thereby provide the visually observable indication. The viscoelastic material can comprise a pressure sensitive adhesive. The visually observable indication can comprise latent indicia which initially are not visible and become visible, obscurable indicia which initially are visible and become obscured, or a combination of both. Various actuating means for selectively switching the indicator from an unactivated state to an activated state are described. Also disclosed are a method for providing a visually observable indication of cumulative thermal exposure and a method for providing a time and temperature integrating device for providing a visually observable indication of cumulative thermal exposure of an object.

Title
Time-temperature integrating indicator device
Application Number
8/402133
Publication Number
5667303
Application Date
March 10, 1995
Publication Date
September 16, 1997
Inventor
David J Yarusso
Shoreview
MN, US
Curtis L Larson
Hudson
WI, US
Theodore P Labuza
Arden Hills
MN, US
Dee Lynn Johnson
Woodbury
MN, US
Russell D Birkholz
Maplewood
MN, US
Robert P Arens
St. Paul
MN, US
Agent
James J Trussell
Walter N Kirn
Gary L Griswold
Assignee
Minnesota Mining and Manufacturing Company
MN, US
IPC
G01K 3/04
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