Ultrasonic liquid level gauge for tanks subject to movement and vibration
US5793705A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Sep 18, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/88
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
One or more high-frequency ultrasonic transducers are used to measure the liquid level of tanks containing any type of fluid, but fuel in particular. The invention relates specifically to tanks that are subject to movement and vibration which generally makes the use of ultrasonic echoes unreliable for obtaining accurate level measurements. A special algorithm is used to obtain the temporal center of the distribution of echo arrival times over a preset time interval. From this temporal center of an echo distribution, the liquid level is readily obtained through the acoustic velocity, time and distance relationship. An annular piezoelectric plate, independently driven at low ultrasonic frequencies (kHz range), mounted on the tank bottom surrounds the high frequency ultrasonic transducer. The function of the piezoelectric plate is to send out propagating ultrasonic waves (essentially longitudinal) to maintain the tank area in the immediate region of the high-frequency transducer free from debris and sediment deposits at the bottom of the tank thereby avoiding the uncertainty in the measurement that is introduced by debris on the tank bottom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.