Fluid overfill probe with anti-reflective guard
US6049088A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1998 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Jan 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/2925
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A optically-based fluid overfill prevention probe has an anti-reflective guard which prevents light external to a prism of the probe from reaching a photodetector of the probe. The probe has a light source which couples light into a prism that is detected by a photodetector when it is internally reflected within the prism. When the prism is contacted by fluid in a container being monitored, the light from the light source exits the prism, and is no longer detected by the photodetector. To avoid the light exiting the prism from being accidentally reflected back into the prism in a direction which would allow it to be detected by the photodetector, the anti-reflective guard is located within a viewing radius of the photodetector, and blocks light external to the prism which might otherwise be detected by the photodetector. The guard is also located within an optimal reflection distance from the prism, so as to prevent the reflection of light exiting the probe back to the photodetector by a reflective surface located between the guard and the prism. The guard preferably includes a wicking portion proximate to the prism that wicks moisture away from a prism surface. The wicking portion…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.