Method and device for measuring fluid velocities
US5218866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1991 |
| Grant date | Jun 15, 1993 |
| Priority date | — |
| Expiry date | Feb 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P13/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The velocity of a fluid in a positive or negative direction is measured by se of a thermistor in a feedback circuit. The temperature of a flow thermistor is balanced with the temperature of a reference thermistor by sensing temperature through resistance by way of its voltage and adding power until the flow thermistor is at the same temperature as the reference thermistor. The ratio of reference power used as compared to flow power is indicative of the fluid's speed. Power is added by sending a signal of varying frequency to the flow thermistor; the reference thermistor is powered by a constant frequency signal. Power is measured by comparing the frequencies of the reference signal to the flow signal. Fluid direction is measured by placing a direction thermistor on either side of the flow thermistor, measuring the temperature of each direction thermistor, the cooler thermistor being upstream of the flow thermistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.