|Series||Atomic Energy of Canada Limited. AECL -- 8270|
|Contributions||Mayo, W., Carter, J.|
Tubing inspection is generally limited to non-ferromagnetic tubing and is known as conventional eddy current testing. Conventional ECT is used for inspecting steam generator tubing in nuclear plants and heat exchangers tubing in power and petrochemical industries. The . The eddy current technique has been applied successfully in this respect to inspect non-ferromagnetic tubes. However, inspection of ferromagnetic tubes by means of eddy currents is more problematic because local variations of the magnetic permeability along the tube can cause disturbing signals and the high incremental magnetic permeability Author: W.H. Van Den Berg, H.L.M. Bakker. The remote field and Near Field™ eddy current techniques for inspecting ferromagnetic heat exchanger tubing are similar in that they both take advantage of low frequencies to penetrate the material without the use of magnetic bias to reduce permeability by saturation or partial saturation. A multi-frequency eddy current technique was developed for the inspection of SSl tubes of intermediate heat exchangers (IHX) in the fast flux test facility (FFTF). The technique enables detection of discontinuities on the outer tube surfaces, while effectively discriminating against the interfering signals caused by the probe motion, tube.
Eddy current array (ECA) is an assembly of single eddy current sensors or coils that are multiplexed in a certain order to obtain the required sensitivity. There are many different designs of eddy current probes, including flexible probes, padded probes or spring-loaded fingers. Figure 3. Calibrating eddy current array equipment. Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review Article (PDF Available) in Chinese Journal of Mechanical Engineering 30(3) April with 1, Reads. Eddy Current Application Eddy current is a noncontact method used to inspect nonferromagnetic tubing. In this technique, the probe is excited with an alternat-ing current, inducing eddy currents in the part under inspection. Any discontinuities or material property variations that change the eddy. Eddy Current Testing, Remote Field Testing and DinsearchTM are electromagnetic techniques and tend to be used as screening tools in order to select tubes for IRIS ultrasonic testing, especially in the case of ferromagnetic materials, e.g. Carbon Steels. FEATURES Up to tubes per day inspected Ferromagnetic and non-ferromagnetic tube inspection.
A new eddy current technique has been developed that does not require the use of magnets. Near field array for ferritic/ferromagnetic stainless steel (NFA FS) is an ET array solution for thorough inspection of thin-walled ferritic/mildly-ferromagnetic tubing capable of detecting and characterizing inside diameter (ID) and outside diameter (OD). Traditionally the remote field eddy current (RFEC) phenomenon has been applied to the inspection of ferromagnetic tubes in heat exchangers, boilers etc. The RFEC probe has an exciter and sensor coil spaced such that most of the magnetic field received by the sensor is due to the field that has diffused through the pipe wall. The phase difference between the exciter and sensor signals is. A velocity induced eddy current probe has been used to detect cracks in both non-ferromagnetic and ferromagnetic metals. The simulation and experimental results show that this probe can successfully detect cracks in both cases, but further investigation shows that the underlying principles for inspecting non-ferromagnetic and ferromagnetic metals are actually different. Since outer diameter defects might not be detected by conventional eddy current testing due to skin effect phenomena, this paper studies the feasibility of using the remote field eddy current (RFEC) technique, which has shown equal sensitivity to inner diameter (ID) and outer diameter (OD) defects in ferromagnetic pipe inspection.