Magnetic Particles Course

Lesson 1 • Magnetic Flux Leakage Concept

Explains how discontinuities disrupt flux and create leakage fields. Directly links physics to defect detectability in MPI.

Lesson 2 • Basic Principles of Magnetism

Covers magnetic fields, poles, flux lines, and permeability. Provides the physics foundation required for all subsequent MPI concepts.

Lesson 3 • History and Industry Applications

Traces MPI development and current industrial uses. Contextualises the method within nondestructive testing (NDT) practice.

Lesson 1 • Magnetisation Using Prods and Coils

Details prod contact technique and coil-wrap methods for field generation. Students apply correct spacing and turn calculations.

Lesson 2 • Multidirectional Magnetisation Systems

Introduces simultaneous or sequential multi-field systems for all-orientation coverage. Students assess when single-pass inspection is appropriate.

Lesson 3 • Direct and Indirect Magnetisation

Contrasts passing current through a part versus inducing a field externally. Establishes the two primary magnetisation categories used throughout the course.

Lesson 4 • Central Conductor and Threading Bar

Explains threading a conductor through hollow parts to create circular fields. Connects technique to inspection of bores and rings.

Lesson 1 • Inherent Discontinuities in Raw Material

Covers seams, laps, pipes, and inclusions formed during casting and ingot processing. Establishes baseline knowledge of material-origin defects.

Lesson 2 • Weld Discontinuities

Details incomplete fusion, undercut, porosity, and weld cracks detectable by MPI. Connects weld process variables to resulting discontinuity types.

Lesson 3 • Relevant vs. Non-Relevant Indications

Distinguishes true defect indications from geometry-caused and false indications. Students apply decision criteria to accept or reject indications.

Lesson 4 • Processing Discontinuities

Examines defects introduced during forging, rolling, welding, and heat treatment. Links manufacturing process to expected defect type and orientation.

Lesson 1 • Particle Application Techniques

Compares spraying, flowing, and dusting methods for uniform particle coverage. Students match application method to part geometry and magnetisation type.

Lesson 2 • Wet Particle Suspensions

Covers fluorescent and visible wet particles suspended in oil or water carriers. Students prepare and maintain bath concentration within specification.

Lesson 3 • Fluorescent Particle Inspection Setup

Addresses UV-A light requirements, darkroom conditions, and eye adaptation. Connects lighting setup to reliable fluorescent indication visibility.

Lesson 4 • Dry Particle Characteristics

Examines particle size, shape, colour, and mobility for dry application. Links particle properties to detection sensitivity on rough surfaces.

Lesson 1 • Magnetisation Adequacy Verification

Uses field indicators, pie gauges, and Ketos rings to confirm adequate field strength. Students interpret results and adjust technique parameters.

Lesson 2 • Pre-Inspection Surface Preparation

Covers cleaning, coating removal, and surface condition requirements before MPI. Ensures students understand how surface condition affects indication quality.

Lesson 3 • Technique Sheet Development

Guides creation of written procedures specifying all inspection variables. Students produce compliant technique sheets for representative part families.

Lesson 4 • Inspection Sequence and Coverage

Establishes systematic part coverage plans to ensure no area is missed. Students map inspection zones and document coverage for complex geometries.

Lesson 1 • AC Coil Demagnetisation Technique

Covers pass-through and withdrawal methods using AC demagnetising coils. Students calculate required coil ampere-turns for part cross-section.

Lesson 2 • Why Residual Magnetism Is Harmful

Identifies operational problems caused by residual fields in finished parts. Motivates demagnetisation as a compulsory post-inspection step.

Lesson 3 • DC Reversal Demagnetisation

Details step-down DC reversal cycles for heavily magnetised or large parts. Connects DC method to parts where AC coil penetration is insufficient.

Lesson 4 • Demagnetisation Theory

Explains the hysteresis loop and how reversing, diminishing fields reduce residual flux. Provides the theoretical basis for all demagnetisation techniques.

Lesson 1 • Reporting Inspection Results

Structures complete inspection reports including part ID, technique, and findings. Students produce reports meeting traceability and quality record requirements.

Lesson 2 • Measuring and Recording Indications

Covers measurement tools, sketching, photography, and tape-lift methods. Ensures accurate, reproducible documentation of all relevant findings.

Lesson 3 • Confirmation and Re-Inspection

Addresses re-magnetisation, cleaning, and re-inspection to confirm ambiguous indications. Builds systematic verification habits before final disposition.

Lesson 4 • Applying Acceptance Standards

Interprets linear, rounded, and clustered indication criteria from written standards. Students make accept/reject decisions on representative sample sets.

Lesson 1 • Equipment Calibration and Traceability

Establishes calibration intervals, standards traceability, and out-of-calibration response. Students manage calibration records within a quality system.

Lesson 2 • Procedure Qualification and Approval

Covers procedure demonstration, approval authority, and change control. Links procedure qualification to consistent, auditable inspection outcomes.

Lesson 3 • Written Practice and Employer Programmes

Explains the employer-written practice document governing NDT qualification. Students draft key sections of a compliant written practice.

Lesson 4 • NDT Personnel Qualification Levels

Defines Level I, II, and III roles, responsibilities, and training requirements. Students identify their certification pathway and scope of authority.