Time-temperature integrating indicator device
US3932134A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1974 |
| Grant date | Jan 13, 1976 |
| Priority date | — |
| Expiry date | Oct 16, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N31/229
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Temperature time integrating indicator device in which a gas generating material located at one end of the device and activated at time of use of the device is absorbed by an indicating wick extending in the device in a direction away from the gas source, which wick changes color to denote a time-temperature integral and hence the temperature history of a product, there being a gas barrier means extending along the longitudinal sides of the wick for inhibiting gas transport to insure that substantially all gas absorbed by the wick makes first contact with the wick at the end nearest the gas source thus precluding first gas contact with the wick at more remote location with consequent erroneous temperature history indication.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.