How to Do Visual Magnetic Particle Inspection in Easy Steps

Visual Magnetic Particle Inspection is a relatively new concept in NDT or non-destructive testing training that helps NDT technicians to detect surface and subsurface discontinuities. Since it is low-cost and time-effective, it’s considered an ideal method during new construction or in-service inspections.

While the best practice to perform Visual Magnetic Particle Inspection under various conditions is better learned in NDT or non-destructive testing training sessions, we thought of guiding you through the process. Let’s see how MP is carried out:

1. Surface preparation: Clean, dry, and get rid of any dirt, grease, paint, scale, or other impurities from the test surface as they can interfere with the inspection. Use a quality SKC-S solvent cleaner/remover.
2. Magnetization set-up: The test surface must be set-up in a way that makes the application of magnetizing current easy. However, this step will be different for different applications. You will be taught about using the right approach in your NDT or non-destructive testing training.
   • Magnetization method: Different ways are used to apply magnetic current to a part or area. Always check the part procedure for the right magnetization method.
   • Amperage: Ensure to consult the part procedure for the most accurate amperage. The amperage may vary depending on the part, type of metal, and defect to be found.
   • Magnetic field strength: Monitor the magnetic field strength using a Pie Gauge, QQI, Hall Effect Meter, known defect or Magnetic Flux Indicator Strip.
3. Apply magnetic current: For dry and continuous method, magnetic current starts before the application of magnetic powder and the magnetic current terminates only after magnetic particle application is done.
4. Apply magnetic particles: Apply the magnetic particles to the test surface or part while applying the current and gently removing the excess magnetic powder. This step can be difficult; therefore, NDT or non-destructive testing is necessary.
5. Inspection: Evaluate the test area or part under appropriate UV lighting conditions. Inspect it for any indication and choose appropriate steps to interpret and document any observation.
6. Additional magnetization: Depending on the test area or part and the process you use for inspection, additional magnetization may be required to find discontinuities in different orientations. In this case, repeat steps for additional magnetization. 
7. Demagnetization: Once the final inspection is complete, demagnetize the part using appropriate magnetic current, field strength, and direction. Later, use a Field Meter to look for any remaining magnetism.
8. Post cleaning: Clean the test part or area after inspection to get rid of any residual magnetic particles.

Bottom Line

If you want to learn Visual Magnetic Particle Inspection Testing to enhance your NDT skills or expand your skill base, consider enrolling yourself in NDT or non-destructive testing training from a renowned institution approved by the state or federal government.

About This Author

NDT Consulting Services Inc. https://www.ndtcs.com/ Joined: February 24th, 2019