Gas flowmeter using thermal time-of-flight principle
US5347876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1992 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Jan 7, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/7084
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A temperature time-of-flight (TOF) sensor is combined with a nozzle of known flow area to create a TOF flowmeter. The TOF measured by the flow sensor provides a measure of gas volumetric flow rate. A TOF sensor has of a pulse heated wire and a single temperature sensor downstream of the wire. This single temperature sensor arrangement allows the accurate measurement of gas velocities much lower than the previously demonstrated limit of 0.3 m/s. The TOF sensor combined with a nozzle creates a new device such that the TOF measured with this device provides a measure of the gas flow rate rather than just the gas velocity. More than one nozzle in series is combined to achieve high flow measuring ranges. Compensation for variations in the thermophysical properties of the gas being metered is provided by pulsing the heated wire and measuring sensor outputs when both are immersed in the gas at zero velocity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.