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:
Mar. 28, 1978
Filed:
Mar. 28, 1977
Applicant:
Inventor:
James Stewart Johnston, Bognor Regis, EN;
Assignee:
Rosemount Engineering Company Limited, Bognor Regis, EN;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01F / ;
U.S. Cl.
CPC ...
73 2 / ; 73204 ;
Abstract
An electric circuit includes three matched resistance thermometer sensors and is responsive to changes in rate of heat loss from at least one of them. The sensors are connected in a series-parallel arrangement to form one arm of a bridge circuit. An amplifier detects imbalance in the bridge and controls current flowing in the bridge to restore balance. Twice as much current flows in one sensor than in the other two, so that the one is maintained hotter. Environmental changes effecting a change in the rate of heat loss from the one sensor are detected as a change in current flowing in the bridge.