Liquid level sensor having a plunger core
US5651285A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 26, 1995 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Apr 26, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/2961
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The liquid level sensor comprises a graduated tape or cable whose free end is fixed to a plunger core that includes a housing and a probe for detecting the presence of a liquid. The probe comprises a metal waveguide having a cylindrical solid top portion, a portion of smaller section constituting a mechanical amplifier, a frustoconical portion, and a cylindrical bottom end portion constituting the sensitive portion of the probe. The metal waveguide is connected to the housing of the plunger core in sealed manner via a support flange which is fixed to the conical portion of the metal waveguide in such a manner that only the portion of the waveguide situated beneath the fixing zone emerges from the housing and can come into contact with a liquid. A transducer electrically powered by electronic processing circuits is disposed at the free end of the top portion and is excited at a predetermined frequency f.sub.i to create incident elastic waves in the waveguide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.