Fluid level detector using thermoresistive sensor
US6098457A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 18, 1999 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Jan 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fluid level detector according to the invention comprises a substrate formed of a heat-insulative material and one or more thermoresistive sensor elements located on the substrate that is adapted to be immersed in a fluid. A current source is connected to the sensor element for producing a current through the sensor element during a predetermined time period. The current heats the sensor element and causes a change in voltage across the sensor element at least during the time period. The amount of change in voltage during the time period is reflective of the fluid level, since the fluid serves as a heat sink for the sensor element. The voltage is measured across the sensor element and a voltage slope is determined. The determined voltage slope is indicative of fluid level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.