The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 1989
Filed:
May. 27, 1988
Thomas R Olson, Chesterton, IN (US);
Dwyer Instruments, Inc., Michigan City, IN (US);
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.