Air flow sensor and detecting method
US5212983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Mar 18, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/698
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pair of thermistors are mounted in a tube which diverts a minor portion of the air flowing through a duct of an HVAC system. One thermistor is heated by a feedback control system to maintain a substantially constant temperature differential between the thermistors. A signal representing the flow velocity is detected by detecting the power which is applied to the heating body to maintain the constant differential. That power represents the thermo power being carried away from the heated body. The temperature of the unheated thermistor is also detected. The signals are converted to digital form and applied to a computer for computing the flow rate in the ducts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.