This testing method is called MT (Magnetic Testing) or MPT (Magnetic Particle Testing), and suitable for the surface / subsurface flaw inspection of ferromagnetic materials.
Principle of MPT is as follows:
- When the workpiece to be inspected is magnetized, magnetic flux is induced.
- If there is a flaw on the surface, magnetic flux leaks into the air at the position of the flaw.
- Then magnetic particles (dyed or fluorescent encapsulated) are applied to the surface.
- These magnetic particles will migrate to the flaw where the magnetic flux leaks and forms a flaw indication that is several tens of times of actual flaw width.
- The inspector visually identifies the flaw.
Level I Technician Course
To provide a basic Knowledge of Magnetic Particle Test and enable a candidate to carry out tests according to an established procedure under supervision of a level II or III personnel. This course is especially designed to provide a sound theoretical knowledge and required practical skill for a level I technician.
MT Level I Technician Responsibilities
To carry out operations as per written procedure/instruction from level II personnel. He shall be able to set up test equipment, calibrate and carry out tests, classify and report the results. He shall not be responsible for the choice of test technique nor for assessment of the test results.
MT Level I Course outline
- Basic of Magnetism
- Magnetisation Techniques
- Inspection Mediums
- Inspection Techniques
- Indication Classification
- Test Equipments and Accessories
- Types of Discontinuities
MT Level I Practical Training
Yokes, Prods, Headshot, Central Conductor, Coil Techniques, Using dry, wet ordinary and wet fluorescent powders, Demagnetisation.
Level II Technician Course
The course is intended to provide detailed instruction in theory and practical such that the personnel shall be able to
- Identify suitability of MT for material and inspection procedure.
- Develop inspection techniques and procedure that shall be followed by level I operator.
- Analyse the test results.
MT Level II Technician Responsibilities
- To select proper test technique and equipment as per established procedure
- To calibrate, set and carry out test or supervise testing by level I Technician
- Prepare test report for acceptance/rejection as per standard
- Have knowledge of merits and limitations of MT and other common NDT methods
- Prepare written procedure for level I operator
- Responsible for care and maintenance of testing equipments and accessories
MT Level II Course outline
- Review of Level-I course
- Selection of Techniques
- Codes, standards and Procedures
- Acceptance Standards
- Manufacturing Process and Discontinuities
- Interpretation of Indications
- Preservation of Indications
- Evaluation of Test Equipment
MT Level II Practical Training
All the practical of Level-I plus Interpretation, evaluation and recording of test results.