Eddy current testing (ET) is a common method of electromagnetic testing used in nondestructive testing (NDT). Before we get into the details of this type of testing, let’s start with the basics!
An eddy is the flowing, circular current of elements like water, smoke, and even air. So, eddy current testing involves using a flowing, alternating electrical current to create eddy currents on conductive material. If an irregularity is present in the material, it will be shown by the disturbance of the eddy currents.
Like other NDT methods, eddy current testing identifies defects in materials early on. Catching flaws ahead of time prevents major problems like creep (deformation caused by stress and elevated temperatures) or catastrophic failure (complete breakdown where recovery is impossible) from occurring in the future. When these problems are stopped, it keeps your rotating equipment and machinery functioning effectively and efficiently. It can also help prevent unexpected downtime, which can potentially save you money if downtime is not factored into the pricing of goods, services, equipment, etc.
Eddy current testing catches issues like cracks, pits, inclusions, and voids on a variety of different materials that are ferrous (metals containing iron) and nonferrous (metals not containing iron). Some metal materials that can be tested are condensers, bearings, spindles, and tubing.
Now that you know what eddy current testing is and how it works, let’s go over its advantages.
There are several benefits of eddy current testing, with the major one being its ability to detect flaws through several layers of material and surface coatings. Other advantages of eddy current testing include:
- The testing equipment is lightweight and small in size, making it easily portable.
- The material requires little preparation or cleaning prior to being tested.
- The test can be conducted without the testing probe coming into direct contact with the object being tested.
- This test is highly sensitive and can detect small cracks on the material’s surface.
- The testing and inspection process can be performed relatively quickly with accurate and reliable feedback.
While eddy current testing has many benefits, the primary downside is that it’s only effective when used on conductive materials. Because the object or material being tested must hold an electrical current flow for eddy current testing to work, non-conductive materials are ineffective.
An eddy current inspection can only be performed by a certified and qualified NDT technician. If you need an eddy current inspection performed at your worksite, contact RRL NDT! We have Level II and Level III certified technicians that can conduct eddy current testing, as well as trainings and certifications. We provide cost-effective eddy current testing and additional NDT solutions to industries and businesses nationwide.