Sensor array i.e. double spiral electro-magnetic acoustic transducer sensor array, for inspecting interior wall of tubular member, has sensor coils lying between and equidistant from opposing edges of two pole magnets

摘要

The array has sensor coils including receiver coils and a transmitter coil. The transmitter coil is located between the receiver coils. A common centerline is oriented at an angle relative to a central longitudinal axis of a magnetic flux leakage inspection tool (20) on which each sensor coil is mounted. The inspection tool has two pole magnets (41, 61) arranged oblique to the central longitudinal axis of the inspection tool. The sensor coils are located on an external surface of the inspection tool, and lie between and equidistant from opposing edges of the two pole magnets.