In the following blog we discuss the most popular types of electromagnetic non-destructive testing techniques. We explain what electromagnetic non-destructive testing is and describe the benefits and drawbacks of each method of electromagnetic NDT.
What Is Electromagnetic Non-Destructive Testing?
Electromagnetic non-destructive testing is a method of NDT used to identify and measure defects in a range of materials used in construction, civil projects and manufacturing amongst other industries. The process involves use of an electric current, magnetic fields or both within a test object. The response the test object gives to these forces determines whether or not there are defects present and can determine whether a part needs to be repaired or replaced. Essentially, background noise registered by a sensor will indicate surface or subsurface defects and the need for adjustment of structural or mechanical components.
Electromagnetic testing is a field of NDT that encompasses a range of techniques. These techniques include:
- Eddy current testing
- Alternating current field measurement
- Magnetic flux leakage testing
- Remote field testing
- Pulsed eddy current testing
- Wire rope testing
- Magnetic particle inspection
Below we describe each method listed above. The use of each method is explained as well as some of their pros and cons.
Eddy Current Testing
Eddy current testing is used to identify surface and subsurface cracks in a material. It is mostly applied to non-ferromagnetic substances. The drawback to this method is that its available testing depth is relatively shallow.
Alternating Current Field Measurement
Alternating current field measurement (ACFM) is very similar to eddy current testing, but is applied to steel parts. It is also limited to shallow components and is most commonly applied in weld testing.
Remote Field Testing
Remote field testing (RFT) is utilised in the evaluation of pipes, steel and tubes. RFT is relatively limited to testing objects in these categories with small diameters and short lengths.
Magnetic Flux Leakage Testing
Magnetic flux leakage testing (MFL) is also used to evaluate pipes, steel and tubes, however it is used to test pipes of a larger diameter and longer length than is possible to inspect using RFT.
Pulsed Eddy Current Testing
Pulsed eddy current testing allows the identification of large-volume metal loss in steel components without subtracting insulation.
Wire Rope Testing
Magnetic flux leakage testing is used in wire rope testing to determine whether wire rope comprising a steel cable is broken.
Magnetic Particle Inspection
Magnetic particle inspection involves sprinkling tiny magnetic particles in the form of a liquid or powder on a magnetised steel surface. Any cracks in the surface can be identified by the collection of these particles in any one particular location.
Buy Electromagnetic Non-Destructive Testing Equipment
NDT Australia supplies electromagnetic non-destructive testing equipment across the nation. Contact us via our contact form or on (02) 9524 0558 to make an enquiry about any of the NDT equipment we have listed on our website. We are available from 7:30am to 4:00pm Monday to Friday.