Eddy Current Inspection
Measuring the effects of induced eddy currents on the primary or driving electromagnetic field is the basis of eddy current testing. The electromagnetic induction needed for eddy current testing is created by using an alternating current. This develops the electromagnetic field necessary to produce eddy currents in a test piece.
Eddy current testing is applicable to any material that conducts electricity and can be performed on magnetic and nonmagnetic materials. The test is therefore applicable to all metals encountered in power station condition assessment work.
Parameters affecting eddy current testing include the resistivity, conductivity, and magnetic permeability of the test material; the frequency of the current producing the eddy currents; and the geometry and thickness of the component being tested.
BWXT uses a variety of probes for the detection, configuration and sizing of indications found in steam generator and heat exchanger tubing. BWXT incorporates the bobbin probe, primarily for volumetric indications such as pitting and fretting, and the X-probe which is a T/R (transmit/receive) array probe used for detection of axial or circumferential indications, along with volumetric indications. There are three types of X-Probes typically deployed for characterization and detection, including a highly specialized tight radius X-probe for traversing low row tubes with tight bends.
BWXT uses the latest technology available to locate, evaluate and size indications in steam generator and heat exchanger tubing. BWXT employs a highly skilled primary and secondary production and resolution analysts. The analysis software uses multiple options for display modes, process channels and multi frequency mixes to determine parameters such as amplitude, phase, location, type of indication and more.