Omnidirectional eddy current probe and inspection system

• Main Authors: PLOTNIKOV YURI A, NATH SHRIDHAR C, MCKNIGHT WILLIAM S, WANG CHANGTING, GAMBRELL GIGI O
• Format: Patent
• Language: English
• Published: 01.12.2005
• Edition: 7
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

An omnidirectional eddy current (EC) probe includes at least one EC channel having a first and a second sense coil that are offset in a first (x) and a second (y) direction and overlap in at least one of the directions (x,y). At least one drive coil is configured to generate a probing field for the EC channel in a vicinity of the sense coils. An omnidirectional EC inspection system includes an omnidirectional EC array probe (ECAP) that includes a number of EC channels and drive coils. Each EC channel includes first and second sense coils with opposite polarities. The drive coils have alternating polarities. Electrical connections perform differential sensing for respective EC channels. Corrective drive coils are disposed at respective ends of the EC channels and generate probing fields. An eddy current instrument is connected to the omnidirectional ECAP and receives differential sensing signals from the EC channels.