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:
Sep. 05, 1989
Filed:
Aug. 08, 1986
Eckhardt Hoenig, Erlangen, DE;
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
An apparatus for measuring magnetic fields which change only at an extremely low frequency contains a SQUID magnetometer which comprises a superconducting flux transformer for inductively coupling the measuring signal into a d-c SQUID sensor. With this apparatus, also quasi-static magnetic fields with frequencies far below 1 Hz should be detectable. A device for modulating the measuring signal to be coupled into the SQUID sensor is associated at least with the flux transformer, the modulation frequency of which is in a frequency range characteristic for low-noise operation of the SQUID. The modulation frequencies are generally above 1 Hz and optionally even above 1 kHz.