Thermal mass flow rate sensor having fixed bypass ratio
US7121139B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2004 |
| Grant date | Oct 17, 2006 |
| Priority date | — |
| Expiry date | Nov 12, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F5/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flow rate sensor includes a main conduit, a sensor tube and a bypass tube connecting an upstream portion of the main conduit to a downstream portion of the main conduit such that flow through the main conduit is divided through the sensor tube and the bypass tube, and at least one heater element for heating the sensor tube. A first flow restrictor of porous media is positioned between the upstream portion of the main conduit and the sensor tube, and a second flow restrictor of porous media is positioned between the upstream portion of the main conduit and the bypass tube. The flow restrictors provide the flow rate sensor with a fixed bypass ratio so that the sensor can operate independently of the type of gas being measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.