Multiple frequency digital eddy current inspection system
Patent 4207520 Issued on June 10, 1980. Estimated Expiration Date: 
April 6, 1998. 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.
April 6, 1998. 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 References 3056081 3422346 3675118 3688186 3701941 3823368 3826976 Non-destructive testing systems having automatic balance and sample and hold operational modes Method and apparatus for measuring cross sectional area and weight per unit length of elongated, conductive material by magnetic field displacement Patent #: 4083002 InventorsAssigneeApplicationNo. 05/893869 filed on 04/06/1978US Classes:324/238, Material flaw testing324/233With phase sensitive elementExaminersPrimary: Rolinec, Rudolph V.Assistant: Snow, Walter E. Attorney, Agent or FirmInternational ClassG01N 27/90 (20060101)AbstractAn apparatus for inspecting for cracks under installed fasteners and the like using a multiple frequency digital eddy current system. A computer with a plurality of digital arrays generate drive signals which are converted to analog and applied to the test coil, a second set of digital arrays generate balance signals, are adjusted in amplitude and phase and drive signals so that the output of the test coil is zero in a test specimen, output signals from a work piece are processed in the computer giving phase-sensitive crack detection.Field of SearchMagnetic sensor within materialSensor supported, positioned, or moved within pipe Combined Plural tests With means to create magnetic field to test material Plural magnetic fields in material With phase sensitive element Electrically energized nonforce type sensor Material flaw testing Material flaw testing Induced voltage-type sensor Material flaw testing Opposed induced voltage sensors Plural sensors Plural sensors Magnetic field detection devices | |
