Piezoelectric device for measuring liquid level
US6588269B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2001 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Sep 26, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/2962
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention concerns a device for measuring liquid level, comprising a detection set (Si) including two piezoelectric cells (10, 12) associated with control means for transmitting ultrasonic waves respectively opposite a reference reflector (16), located at a known distance (D) from the associated cell, and from the top surface (14) of the liquid, and processing means for determining the level of liquid by operating on the respective propagation times of the ultrasounds emitted by each of the two cells (10, 12). The invention is characterised in that it comprises means for defining, after the device has been charged, an initialising phase (1100, 1100 bis) during which the control means control the piezoelectric cells (10, 12) such that the ratio between the excitation rate of the reference cell (12) and that of the level-measuring cell (10) is higher than the ratio between those same rates during the subsequent stabilised measuring phase (1300).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.