Process and system for operating a level sensor
US5719332A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1995 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | May 26, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/247
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A process and a system for operating a level sensor, particularly for measuring amounts of liquid in motor vehicles, employs a plurality of heatable thermistors wherein a number of the thermistors are covered by liquid depending on the level of the liquid, and are cooled below a breakpoint temperature of the thermistors. The total resistance of the thermistors, which may be connected with further resistors, changes discontinuously as a function of the liquid level. At least one thermistor is located above the maximum possible level. The temperature of the thermistors is increased to such an extent by a feeding of electrical heating power that all thermistors which are above the existing level exceed their breakpoint temperatures, whereupon the total resistance is measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.