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:
Nov. 26, 1991
Filed:
Aug. 01, 1989
Applicant:
Inventors:
Frederic Broyde, Rueil Malmaison, FR;
Michel Barrault, Saint Ismier, FR;
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
324627 ; 324616 ; 324603 ; 375-1 ;
Abstract
An emitter assembly of low-power electromagnetic signals with random or pseudo-random frequency variation is located inside an electromagnetic shield to be monitored. These signals are detected by at least one synchronous detection receiver located outside the shield, a second transmission channel, preferably constituted by an optic fiber, connecting the emitter and receiver assemblies to enable synchronous detection of signals transmitted via an electromagnetic channel through the shield. The amplitude of the electromagnetic signals received by the detector is significant of the quality of the shielding.