Liquid crystal cumulative dosimeter
US4066567A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 1976 |
| Grant date | Jan 3, 1978 |
| Priority date | — |
| Expiry date | Feb 4, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S252/962
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Cumulative temperature dosimeter utilizes a temperature dependent reaction in a cholesteric liquid crystal composition to produce a color change indicative of temperature exposure over a period of time. Typically, the composition includes, as a solvent, a cholesteric liquid crystal, such as a mixture of p-methoxy-p'-n-butyl-azoxybenzene, cholesteryl nonanoate, cholestyl chloride, and cholesteryl oleyl carbonate. One or more solutes are included, the solutes being reactive at a rate which is temperature dependent, to cause either generation or consumption of mesogenic compounds. In turn, the pitch of the solvent, observable as a visible color change, is affected in proportion to the cumulative temperature exposure of the composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.