Filling-level indicator
US5042298A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1990 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Feb 16, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/296
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a filling-level indicator (12), especially for fuel tanks (10) of motor vehicles, flexural waves of the frequency (f) are fed into a sound conductor (11) via a transmitter (13). For the temperature compensation of the zero point of the filling-level indicator (12), the temperature coefficient of the modulus of elasticity (TKE) of the material of the sound conductor (11) will be at least of the order of magnitude of the negative amount of the temperature coefficient of the longitudinal extension (TKL). Furthermore, it has been shown to be especially advantageous to feed the flexural waves at a frequency f.sub.opt .apprxeq.50 kHzmm/d, (d) being the thickness of the sound conductor (11). A temperature compensation of the measuring sensitivity of the sound conductor is possible as a result of this measure. The filling-level indicator thereby supplies relatively accurate measurement values and is virtually independent of temperature influences within a wide temperature range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.