what is magnetic particle testing

What is Magnetic Particle Testing

PRINCIPLE

Magnetic Particle testing is based on inducing magnetic field in parts and then looking for breaks in magnetic fields caused by surface discontinuities. MT testing includes methods for magnetization and  magnetic mediums such as particles. During MT testing, a magnetic field is applied and magnetic particles sprayed (wet) or dusted and floated (dry particles). An accumulation of magnetic particles is an indication of potential discontinuity. The method is applicable to magnetic materials.

EQUIPMENT

Magnetization equipment: AC or DC yokes, coils,  head shot setup that pass current directly through the part, etc. Magnetic mediums include high permeability particles coated with visible or fluorescent dyes. Particles can dry powder or in a wet suspension. Other auxiliary equipment includes pie gauge, shims, gauss meter and a 10 lb weight for AC yoke.

APPLICATIONS

Applications include inspection of pipes, shafts, turbines, welds, forgings, etc.

INDUSTRY CODES

  • ASME V, Article 7

TRAINING

  • MT Level II, Course no – NDT-102 (includes Level I)
  • Duration – 24 hours