Dual temperature indicator
US5215378A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 17, 1992 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Apr 17, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K3/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dual temperature indicator providing visual indications when exposed to predetermined high or low temperatures. The indicator has a bulb with a capillary tube and an attached high temperature indicator structure. The bulb has a first liquid which also fills a predetermined portion of the tube. A separating substance and a second miscible liquid further fills a predetermined portion of the remainder of the tube. At a predetermined low temperature, the liquid in the bulb contracts causing the separating substance and a portion of the second liquid to move into the bulb to produce a visible color change. The high temperature indicator structure has an indicating member in contact with the capillary tube end and which provides a visual indication at a predetermined high temperature when the liquids expand upon an environmental temperature increase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.