Critical temperature indicator
US4457252A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 9, 1982 |
| Grant date | Jul 3, 1984 |
| Priority date | — |
| Expiry date | Nov 9, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A critical temperature indicator is provided utilizing the volume reduction characteristics of organic compounds as they undergo a change from the liquid state to the solid state. The bulb and a portion of the capillary tube of a thermometer-like structure contains a colorless organic compound. Another organic compound saturated with a dye, which compound has a solidification temperature lower than that of the colorless compound and which is miscible with the colorless compound, is located in the capillary tube and separated from the colorless compound by a solid, movable plug or a liquid which is immiscible with either the colorless or the dyed compound. The volume of the colorless compound upon solidification is less than the volume of the bulb so that the separating plug or liquid and at least a portion of the dyed compound are drawn into the bulb upon solidification. The dyed compound then mixes with the colorless compound to provide a visual indication that the colorless compound has solidified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.