Active shielding device based on SQUID and feedback therefrom for the reduction of environmental magnetic noise
Patent 5367259 Issued on November 22, 1994. Estimated Expiration Date: 
May 12, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 12, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMagnetic compass compensation system Single frequency noise reduction circuit for squids Superconducting magnetic field sensing apparatus having digital output, on-chip quantum flux packet feedback and high bias margins Patent #: 5248941 InventorsAssigneeApplicationNo. 881795 filed on 05/12/1992US Classes:324/248, Superconductive magnetometers505/846Using superconductive quantum interference device (i.e., SQUID): (Class 324/248)ExaminersPrimary: Snow, Walter E.Attorney, Agent or FirmInternational ClassG01R 033/035Foreign Application Priority Data1991-05-13 JPAbstractA magnetic noise reducing device can effectively produce a practically noiseless space that can reduce environmental magnetic noise harmful for measuring biomagnetism with a high magnetism damping factor in low frequency range. The magnetic noise reducing device comprises a SQUID flux meter 1 and a pair of noise canceling coils 2 as minimum components, the feedback current I produced by the SQUID flux meter 1 being supplied to the noise canceling coils 2, the magnetic flux detecting coil of the SQUID flux meter being arranged within a specific central space 4 defined by the noise canceling coils 2 for effective reduction of magnetic noise within that space. | |
