Thermal type flow meter including a secondary heating device to suppress heat transfer
US7587938B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2007 |
| Grant date | Sep 15, 2009 |
| Priority date | — |
| Expiry date | Jan 25, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/698
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A thermal gas-flow measuring instrument has a first heating resistor placed in the gas to be measured. A temperature sensing resistor is positioned upstream or downstream of the first heating resistor and generates signals relating to the flow rate. Between the first heating resistor and the support for supporting the first heating resistor is a second heating resistor that is electrically insulated from the first heating resistor. The second heating resistor suppresses the heat being transferred from the first heating resistor to the support. A control circuit controls the temperatures of the first heating resistor and the second heating resistor so that the operational temperature range of the second heating resistor or the temperature range at the joint section between the first heating resistor and the second heating resistor is at or above the temperature at which water droplets evaporate to disappear by film boiling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.