Method of and device for fluid surface detection using an ultrasonic transducer
US5428997A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 20, 1992 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Jul 20, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02836
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a method of detecting a fluid surface and a circuit for an ultrasonic transducer for detecting such a fluid surface. In accordance with the method, an ultrasonic transducer driver generates a first voltage proportional to the resonant frequency of the ultrasonic transducer. A reference voltage is generated and the reference voltage and the first voltage are monitored and compared, and a surface detect signal is generated when the first voltage drops below the reference voltage. The circuit of the invention includes means for generating a first voltage proportional to the resonant frequency of the transducer, means for generating a reference voltage, and a comparator for monitoring the first and reference voltages and generating a surface detect signal when the first voltage drops below the reference voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.