Optical liquid-level sensing apparatus
US4880990A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1988 |
| Grant date | Nov 14, 1989 |
| Priority date | — |
| Expiry date | Jun 13, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/904
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical sensor element provides cantilevered support of a bent length of glass-rod core of first refractive index having a cladding of second refractive index that is less than the refractive index of the core, and wherein the outer radius of the bend (which may be a single bend, or a plurality of spaced bends) is at least the diameter of the cladded core. Provision is made at the respective ends of the cladded core for completing a light circuit via the length of the cladded core, and flexible leads, as of multi-mode optical fiber, enable completion of the optical circuit to a remotely located control unit having an electrically powered light source and a photodetector, at the respective ends of the circuit. Provision of threshold-operated circuitry at the control unit enables automatic electronic evaluation (and further-remote output delivery) of signals which reflect (a) one or more detected light levels, (b) interface level between two mingled liquids having different specific gravity, and (c) the monitored integrity of the optical circuit as a whole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.