Optical liquid level detector using dual varying light emitters
US5274245A · kind A · utility
33Cited by
2References
9Claims
0Family size
Inventor
Key dates
| Filing date | Nov 6, 1992 |
| Grant date | Dec 28, 1993 |
| Priority date | — |
| Expiry date | Nov 6, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/2921
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for detecting a specific liquid level, that can be mounted externally on a transparent or translucent vessel wall, and is insensitive to ambient light. This device utilizes a single light detector and a pair of AC activated light sources. The light sources produce reflected light signals which, when balanced at the detector, cancel. When liquid is absent the light signals are balanced, and no signal is detected. When liquid is present the extra signal reflected by the meniscus causes the light signals to become unbalanced, and a signal is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.