Electricity: measuring and testing – Magnetic – Magnetometers
Patent
1988-02-02
1989-02-14
Eisenzopf, Reinhard J.
Electricity: measuring and testing
Magnetic
Magnetometers
324259, G01R 3335
Patent
active
048049158
ABSTRACT:
An apparatus for measuring magnetic fields that change at extremely low frequency contains a SQUID magnetometer having a super-conducting flux transformer for inductively coupling the measuring signal into a direct current SQUID sensor. Quasi-static magnetic fields that have frequencies far below 1 Hz are detected. The flux transformer has two inductively coupled windings. At least one winding is arranged on a first carrier element (chip) that enclose a common coupling hole. A second carrier element (counter chip) is attached to the first carrier element. A super-conducting oscillating diaphragm is positioned opposite the coupling hole. The mutual inductance of the windings is modulated with this super-conducting vibrating diaphragm through appropriate changes of the effective size of the coupling hole with a frequency that lies in a characteristic frequency range for low-level noise operation of the SQUID.
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Eisenzopf Reinhard J.
Siemens Aktiengesellschaft
Solis Jose M.
LandOfFree
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