Mass-flow sensor heating element protection method and apparatus
US7084378B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 26, 2004 |
| Grant date | Aug 1, 2006 |
| Priority date | — |
| Expiry date | Apr 29, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/6986
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A heating element protection apparatus for a mass-flow sensor may include a heating element disposed in a gas, a gas temperature sensor disposed in the gas to sense a temperature of the gas, a slope detector to measure a slope of the temperature as power is supplied to the heating element, and a heating element controller to supply power to the heating element to replace heat dissipated by the gas. The heating element controller may detect a temperature of the heating element and may supply power to the heating element based on the heating element temperature and the gas temperature, and the power may be switched off for a predetermined period of time if a magnitude of the slope is greater than a reference magnitude.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.