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:
Jul. 31, 1990
Filed:
Oct. 25, 1988
Applicant:
Inventor:
Frank E Lowther, Plano, TX (US);
Assignee:
Atlantic Richfield, , US;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; G01R / ;
U.S. Cl.
CPC ...
324220 ; 307309 ; 324235 ; 324240 ; 324251 ; 324258 ; 338 / ;
Abstract
Relatively minute changes in magnetic field intensity are sensed by a circuit including a wire coil connected to a Hall effect element to provide the bias current to the element. The Hall effect element is disposed in the magnetic field with the coil and the output signal of the element is proportional to the square of the intensity of the magnetic field. The circuit is included in a device for measuring magnetic anomalies such as stress or corrosion cracks in structures of magnetic material including fluid transmission pipelines.