Air velocity transmitter device
US4860583A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 27, 1988 |
| Grant date | Aug 29, 1989 |
| Priority date | — |
| Expiry date | May 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P5/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument probe has two sensing elements; one is a self heated thermistor that serves as the air velocity sensor, and a second sensing element in the form of a chip thermistor, that are separately but simultaneously exposed, in the use of the instrument probe, to the air flow, with the self heated thermistor and the thermistor chip are incorporated in a self regulating bridge circuit, that, when the unit is powered, generates a non-linear signal that is applied to signal processing circuitry within the unit housing to adjust same for gain and off set with the resulting signal being applied to a linearizer circuit also within the unit housing wherein the signal is electronically processed to supply the unit output signal in the familiar 4-20 milliamp range. The transmitter device is arranged to be powered by either an alternating current or direct current supply that is in the range of about 22 volts to about 28 volts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.