Resonant tube level sensor
US6696962B2 · kind B2 · utility
Inventor
Key dates
| Filing date | May 14, 2001 |
| Grant date | Feb 24, 2004 |
| Priority date | — |
| Expiry date | Jan 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/2967
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Acoustic level sensing by creating, or failing to create, resonance in a tube having a free end. An acoustic transducer at one end of the tube injects sound at a frequency that could produce resonance, depending on whether the free end is open or closed. The drive to the acoustic transducer is then removed, and the sound decay in the tube is monitored to determine if resonance occurred. Based on that determination, a signal is produced that indicates whether a material has or has not closed the free end of the tube. Beneficially, the same acoustic transducer that produces the sound monitors the sound decay. To determine whether resonance has occurred, or to verify system operation, the sound decay at the possible resonant frequency can be compared to the decay at another frequency. Temperature compensation can be performed by attempting to produce resonance at a plurality of frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.