Integrated time-temperature or radiation-dosage history recording device
US4389217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1980 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | Nov 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K3/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A recording device is described, useful as an integrated time-temperature or radiation-dosage history indicator. The device contains a substrate having deposited thereon at least two indicating units, one being unreacted and representing zero time of exposure and the other unit being pre-reacted. Each unit is comprised of an acetylenic compound containing at least one --C.tbd.C--C.tbd.C-- group, capable of reacting by 1,4-addition polymerization thereby forming an end-point color after an irreversible, progressive color change upon thermal annealing or exposure to actinic radiation. The end-point color represents an integrated time-temperature history of thermal annealing or radiation-dosage history. Each unit is constructed such that the time required to form the end-point color by thermal annealing at a given temperature or for a known thermal history, or exposure to actinic radiation at a given average radiation dosage rate, is predetermined. A process is also described for using the device as well as an article having the device affixed thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.