Magnetic Particle Testing

This lesson introduces Magnetic Particle Testing (MT) as a non-destructive testing method and establishes the foundation for understanding the ISO 9712 and SNT-TC-1A certification systems used throughout the world. You will learn the fundamental principles of MT, understand why it is restricted to ferromagnetic materials, and gain a clear understanding of the responsibilities assigned to each certification level. This knowledge is essential for all subsequent lessons, where we will build upon these concepts to develop your practical inspection skills. Topics: What is Magnetic Particle Testing?, Materials and Magnetism, Certification Systems, Terminology and Concepts. Learning outcomes include: Define Magnetic Particle Testing and explain its basic principle of operation.; State the intended use of MT; Distinguish between ferromagnetic, paramagnetic, and diamagnetic materials and identify which are suitable for MT.; Explain the difference between non-destructive testing and destructive testing, including the role each plays in quality assurance..

This lesson explains the physics underlying Magnetic Particle Testing. You will learn how materials become magnetised, how magnetic fields behave, and which material properties control sensitivity, magnetising current requirements, and demagnetisation difficulty. Understanding these principles is essential for selecting the correct magnetising techniques, interpreting indications accurately, and troubleshooting problems in the field. When you understand why MT works, you can make informed decisions about how to apply it effectively. This knowledge will be applied repeatedly in later lessons as you learn to select currents, understand indication characteristics, and explain why some inspections are straightforward while others present challenges. Topics: Atomic and Domain Theory of Magnetism, Magnetic Quantities and Relationships, Hysteresis Loop and Material Properties, Types of Magnetising Current. Learning outcomes include: Describe the atomic and domain theory of magnetism and explain how it applies to ferromagnetic materials.; Explain the behaviour of magnetic poles and state the Law of Magnetism.; Define magnetic flux, flux density, and field strength, and explain their significance in MT.; Define permeability, reluctance, residual magnetism, retentivity, and coercive force..

This lesson introduces the range of equipment used in Magnetic Particle Testing, from portable electromagnetic yokes to stationary bench units with integrated baths. You will learn how each type of equipment generates magnetic fields, when to select each type, and the specific verification requirements. Understanding your equipment is essential for effective MT inspection. The right equipment selection depends on part size, geometry, accessibility, production volume, and the types of discontinuities you need to detect. Equally important is knowing how to verify that your equipment is functioning correctly—this is a fundamental quality control requirement that protects both the integrity of your inspections and the safety of the components you test. Topics: Portable Equipment, Stationary Equipment (Bench Units), Lighting Requirements, Field Indicators and Quality Control. Learning outcomes include: Describe the function and operation of portable electromagnetic yokes and state the restrictions on yoke types.; Explain the features and applications of portable power packs and prod units.; Describe the components and operation of stationary MT bench units.; State the requirements for UV-A (black light) intensity and warm-up period..

This lesson covers the specific techniques used to create magnetic fields in test pieces for Magnetic Particle Testing. You will learn how to choose between circular and longitudinal magnetisation based on expected discontinuity orientation, and how to calculate the magnetising currents required for various part geometries. Understanding magnetisation techniques is central to your role as an MT technician. The effectiveness of any MT inspection depends on achieving the correct field strength and direction. Too little magnetisation and you will miss discontinuities; too much and you will obscure them with background noise. Wrong direction and cracks may go undetected. This lesson brings together the physics you learned in Lesson 02 and the equipment knowledge from Lesson 03, showing you how to apply them in practice. Topics: Fundamental Principles, Circular Magnetisation Techniques, Longitudinal Magnetisation Techniques, Current Type Selection. Learning outcomes include: Explain the Right-Hand Rule and apply it to determine field direction from current direction.; State the relationship between magnetic field direction and discontinuity detection sensitivity.; Distinguish between circular and longitudinal magnetisation and select the appropriate method based on expected discontinuity orientation.; Describe and apply the Head Shot technique for circular magnetisation of solid parts..

This lesson covers the magnetic particle media used in MT inspections—both wet and dry methods—and the quality control procedures required to ensure consistent test sensitivity. You will learn how to prepare and maintain particle suspensions, perform the settling test to verify concentration, and conduct system performance checks. Quality control is not optional in MT—it is fundamental to reliable inspection. A bath that is too dilute will miss defects; one that is too concentrated will create excessive background. Contaminated media will give false indications. Without proper quality control, you cannot trust your inspection results. Topics: Magnetic Particle Properties, Wet Method, Settling Test (Concentration Test), System Performance Verification. Learning outcomes include: Describe the properties required of magnetic particles for effective MT.; Compare and contrast wet and dry particle methods, including advantages and limitations.; Distinguish between fluorescent and visible (colour contrast) particles and their applications.; Explain the preparation and maintenance of wet particle baths..

This lesson defines the mandatory requirements for magnetic particle inspection procedures. You will learn the essential elements that must be included in a written procedure, the strict scanning protocols for weld inspection (including overlap and directional requirements), and the specific restrictions on inspection through coatings. This lesson ensures that Level II personnel can develop, understand, and execute compliant inspection techniques. Following proper procedures is not just good practice—it is essential for consistent, reliable detection of discontinuities and is required for audit compliance. Topics: Written Procedure Requirements, Magnetisation Requirements, Weld Inspection Techniques, Coating Restrictions. Learning outcomes include: List and explain the 14 minimum information items required in an MT procedure.; Explain the requirement for two-directional magnetisation.; Describe the scanning overlap and placement requirements for weld inspection.; State the restrictions on inspection through coatings..

This lesson covers the interpretation of magnetic particle test results—arguably the most critical skill for an MT Level II technician. You will learn to distinguish between relevant, non-relevant, and false indications, and understand the criteria for determining relevancy. Correct interpretation separates a competent inspector from one who either rejects good parts unnecessarily (costly) or accepts defective parts (dangerous). Understanding the causes of different indication types and knowing how to verify your interpretation are essential skills. Topics: Definitions, Non-Relevant Indication Causes, Determination of Relevancy, Interpretation Strategy. Learning outcomes include: Define indication, relevant indication, non-relevant indication and false indications.; List and describe common causes of non-relevant indications.; Describe the process for determining relevancy .; Identify typical indication appearances for cracks, seams, laps, porosity, and lack of fusion..

This lesson covers the principles, methods, and requirements for demagnetisation. After magnetic particle testing, parts often retain residual magnetism that can interfere with subsequent operations such as machining, welding, or use in magnetically sensitive environments. Understanding when demagnetisation is required, how to accomplish it effectively, and how to verify acceptable residual field levels is an essential skill for MT personnel. Topics: Understanding Residual Magnetism, Demagnetisation Principles, Demagnetisation Methods, Verification. Learning outcomes include: Define residual magnetism and explain why it can be problematic.; Explain the relationship between retentivity, coercive force, and demagnetisation difficulty.; State the requirements for when demagnetisation is required.; Describe the fundamental principle of demagnetisation..

This lesson covers the essential safety and environmental hazards associated with Magnetic Particle Testing. MT involves electrical equipment, UV radiation, flammable materials, and chemicals that present various hazards to personnel and the environment. Understanding these hazards and following proper safety procedures is a fundamental responsibility for all NDT personnel. Safety is not optional—it is an integral part of every MT inspection. A thorough understanding of the hazards and their controls protects you, your colleagues, and the integrity of the parts you inspect. Topics: UV Light Safety, Electrical Safety, Arc Strikes, Chemical and Fire Hazards. Learning outcomes include: Identify the primary hazards associated with MT operations.; Describe the safety precautions for using UV-A (black light) equipment.; Explain the electrical hazards of MT equipment and appropriate precautions.; Describe the risks of arc strikes and the requirements for their treatment..

This final lesson covers the documentation and process control requirements for magnetic particle testing. Proper documentation is the final step in the MT process—it provides objective evidence that the inspection was performed correctly, enables traceability for quality assurance purposes, and is critical for audit compliance. Without proper documentation, an inspection might as well not have been done. Records protect the inspector, the employer, and ultimately the end user of the inspected product. Understanding what to document and how to document it is an essential competency for all MT personnel. Topics: Record Requirements, Process Control Documentation, Indication Documentation, Record Requirements. Learning outcomes include: List and explain the record requirements for MT inspections.; Explain the purpose and importance of process control documentation.; Distinguish between a procedure and a technique sheet/written instruction.; Describe how to document relevant and non-relevant indications..

Scored assessment for Magnetic Particle Testing. Covers the LMS lesson content for this course.