EDDY CURRENT TESTING

Transcription

1 NEW SOUTH WALES TECHNICAL AND FURTHER EDUCATION COMMISSION EDDY CURRENT TESTING NSW Module Number: Implementation Date: 6161C 01-Jan-1998 National Module Code: EA605 MANUFACTURING AND ENGINEERING MECHANICAL & MATERIALS PROGRAM AREA

2 1. MODULE DETAILS: 1.1 Module Name: Eddy Current Testing 1.2 Nominal Student Hours: 72 hours This module is equivalent to two standard modules and so will normally require 72 hours for delivery. 1.3 Module Codes: NSW Module Number: National Module Code: 6161C EA Field of Education Code: Chemical Engineering 1.5 Copyright Information: (c)commonwealth of Australia 1.6 Licensing and Franchise Arrangements: Licensing and franchising arrangements are to be negotiated with the Australian National Training Authority (ANTA) (03) MODULE PURPOSE The purpose of this module is to enable students to operate eddy current equipment and interpret signals indicated by the equipment, and to use eddy current test procedures in industrial applications. This module meets the training requirements of AS "Non-destructive Testing and Qualification and Certification of Personnel - General Engineering" for Level 2 certification in eddy current testing. 3. PREREQUISITES Nil 4. RELATIONSHIP TO COMPETENCY STANDARDS: Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 2

3 This module fully addresses the National Metal and Engineering Competency Standards Unit MEM24.6AA Perform eddy current testing in developing generic skills. To achieve full workplace competence for Competency Standards Unit MEM24.6AA, the learner will need to have undertaken relevant on the job skill practice. This can be as either part of the module learning process, after completion of the module or through previous experience. 5. CONTENT: 1. Basic principles Electricity Direct current Amperage Voltage Ohms law and resistance Conductivity and resistivity Alternating current Amplitude Phase Impedance Vectorial representation Electromagnetic induction Field generated by a current Filed/induction relationship Flux of induction vector EMF of induction Self-inductance - coefficient of Mutual inductance - coefficient of Coupling coefficient Impedance of circuit in presence of another circuit Representation of impedance plane Effect of fill factor Normalised impedance plane Effect of frequency Influence of magnetic field Resonant frequency Magnetism Magnetic data Induction and magnetic fields Magnetic permeability Iron magnetisation Induced magnetic flux Lines of force and force fields Flux conservation, residual magnetism Magnetic Ohm law Magnetomotive force Reluctance Magnetic circuits Electromagnetism Magnetic field produced by a current Inductive current - eddy current Reactance - field made by eddy current Biot and Savant law Definition Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 3

4 Practical (right hand) rules Amperes law Definition Applications (toroid, infinite coil, flat coil) Lenz law Definition Auto-induction factor Mutual induction factor Coupling factor Induced currents Short circuit coil Metallic mass Skin effect Reactance 2. Theory of eddy currents Distribution of eddy currents Plane conductors Effect of amplitude and phase Depth of standard penetration Defect reaction according to its position Cylindrical bars Similarity law Characteristical frequency Variation of amplitude and currents Depth of standard penetration Defect reaction according to its position Tubes Characteristical frequencies Variations in amplitude and phase of currents Depth of standard penetration Defect reaction according to its position Geometric defect characterisation Hypothesis of interrupted current Point defects Large defects Multiple defects Impedance diagrams Encircling coil with bar, tube or sphere Operating points, choice Use of impedance diagrams 3. Characteristics of eddy current probes Induction and reception functions Absolute and differential measure Types of probes - Encircling, internal, surface, hybrid Means of focussing Field from an empty coil, divergence between theory and practice Effect of coupling EC distribution related to coil position Field generated by non-load inductor EC path in product according to its position towards inductor coil Distance influence on coupling in various shapes Probe reactance to small, long and continuous defects Design technology, manufacturing technology, electric parameters Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 4

5 maintenance Remote field techniques Magneto-optical imaging 4. Eddy current equipment Working principles Transmission Reception Data presentation Equipment controls Oscillator - frequency control Energising devices and measure-ment Balancing the system Amplifier, filter, modulation/demodulation Phase rotation Display - ellipse, A-scan, vector point Gain control Types of equipment Mono-parameter, mono-channel Multi-parameter, multi-channel Auxiliary devices Signal acquisition Saturation magnetiser/demagnetiser Signal storage Recorders Memories Data processing 5. Properties of materials Physical properties Electrical conductivity Effect of chemical analysis Temperature Grain size Texture Cold work Structure Magnetic permeability Effect of chemical analysis Temperature Grain size Texture Cold work Structure Hysteresis loop Rayleigh area Saturation Weiss area Curie point Anomalies relating to manufacture and service Applications of eddy curry testing 6. Influence of various parameters on eddy current measurement Defect position and orientation EC path Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 5

6 Penetration depth Zone of probe action Material temperature Heating Deviations Compensation Structure and geometry of test part Choice of frequency Phase discrimination Noise filtering Magnetic saturation Coupling influence Vibrations Centering Fill factor Sensitivity Compensation Relative speed Testing frequencies according to speed Band width of apparatus according to test speed 6. ASSESSMENT STRATEGY The assessment of this module is holistic in nature and requires the demonstration of the knowledge and skills identified in the module content, and the integration of that knowledge with those skills. To be successful in this module, the student must show evidence of achievement of the module purpose. Additionally, the module is graded and so allows the student to demonstrate greater depth and/or breadth of achievement. The assessment scheme is designed to assess essential knowledge and skills in a variety of ways throughout the module's assessment events. 7. LEARNING OUTCOME DETAILS 7.1 Learning Outcome 1: Describe the basic principles of eddy current testing. Explain the physics of electricity and magnetism as it applies to eddy current testing. Explain the physics of electromagnetism. Discuss the relevant laws of electromagnetism and electromagnetic induction in relation to the production of eddy currents. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 6

7 7.2 Learning Outcome 2: Describe the theory of eddy currents. Describe how eddy currents are distributed in sheet, plate, bars and tubes. Describe how defects may be characterised for eddy current determination. Explain the use of impedance diagrams in eddy current testing. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. 7.3 Learning Outcome 3: Describe the characteristics of eddy current probes. Describe the induction and reception functions of eddy current probes. Discuss the features and applications of absolute and differential probes. Illustrate the design technology and manufacturing technology of eddy current probes. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. 7.4 Learning Outcome 4: Describe the principles underlying the use of eddy current test equipment for the inspection of materials and components, and set up the equipment. Describe the principles of the operation of eddy current equipment. Set up and calibrate the various types of eddy current equipment. Use eddy current equipment for inspection of materials and components for thickness gauging, Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 7

8 flaw detection, and conductivity. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. 7.5 Learning Outcome 5: Describe the applications for eddy current testing, including the materials and products that may be tested by this method and the nature of the defects that may be detected. Describe the electromagnetic properties of materials that affect their suitability to eddy current testing and the effect of variations in electromagnetic properties on the test outcomes. Describe and identify the main types of defects and discontinuities that may be detected by eddy current testing. Describe the discontinuities in materials that may result from methods of manufacture or service. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. 7.6 Learning Outcome 6: Discuss and assess the influence of various parameters on the eddy current test. Describe how parameters such as defect orientation and position, structure, shape, coupling and test speed may influence the technique and outcome of eddy current testing. Assess and report on the effect of various parameters on the test outcomes. Assessment method Written test to include multi-choice, short answer and essay questions to cover the theory and practical work. Students will also be assessed on the reports submitted on practical assignments. Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 8

9 8. DELIVERY DELIVERY STRATEGY This module may be delivered either in an off-the -job environment or, where suitable resources are available, in an on-the-job environment. It would be expected that all learners should be exposed to the testing that make up the module even in those cases where the learning outcome requires only that they should be able to verify, understand, assess results and recommend action. RESOURCE REQUIREMENTS Suitable physical resources should be available to carry out each of the tests that are included in the module. OCCUPATIONAL HEALTH AND SAFETY REQUIREMENTS Learners should be made aware of the occupational health and safety implications at all times. Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 9

10 B. TAFE NSW implementation requirements 1. Module(s) replaced by this module: 2.1 TAFE Advanced Standings: Arrangements Target Modules Source Modules No : C Eddy Current Testing 6132A Eddy Current Testing Start : End : Sponsor: Manufacturing and Engineering 3. Standard Exemptions: EA605 A student is eligible for an exemption in this TAFE NSW module if they provide documentary evidence from a Recognised Training Organisation that they have successfully completed the national module/s with the specified national module code/s. 4. Recognition of Prior Learning: Students who have completed formal training or who have relevant life/work experience and consider they are able to meet the module purpose, may seek recognition of their prior learning. Applicants will be required to present evidence of their relevant skills and knowledge in an interview with specialist staff. This evidence will be validated either through satisfactory supporting documentation or support from a recognised industry or workplace representative or a challenge test, or other appropriate assessment practice. 5. Module Included in the following Courses: Number Ver Course Name Sponsor Manufacturing Technology Manufacturing and Engineering Manufacturing Technology Manufacturing and Engineering Manufacturing Systems Manufacturing and Engineering Manufacturing Systems Manufacturing and Engineering Quality Systems Manufacturing and Engineering Quality Systems Manufacturing and Engineering Metal and Engineering Competency Standards Manufacturing and Engineering Units Engineering - Higher Engineering Trade Manufacturing and Engineering Non-Destructive Testing Manufacturing and Engineering Non-Destructive Testing Manufacturing and Engineering Engineering - Higher Engineering Trade Manufacturing and Engineering Mechanical Engineering Manufacturing and Engineering Naval Architecture Manufacturing and Engineering Mechanical Engineering Manufacturing and Engineering Naval Architecture Manufacturing and Engineering Mechanical Technology Manufacturing and Engineering Naval Architecture Technology Manufacturing and Engineering Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 10

11 B. TAFE NSW implementation requirements Engineering Manufacturing and Engineering Engineering Manufacturing and Engineering Non-Destructive Testing Manufacturing and Engineering Materials Technology Manufacturing and Engineering Manufacturing Technology Manufacturing and Engineering Manufacturing Technology Manufacturing and Engineering Manufacturing Systems Manufacturing and Engineering Manufacturing Systems Manufacturing and Engineering Quality Systems Manufacturing and Engineering Quality Systems Manufacturing and Engineering Materials Technology Manufacturing and Engineering Materials Technology Manufacturing and Engineering Engineering - Technician Manufacturing and Engineering Metal & Engineering Competency Standard Manufacturing and Engineering Units Mechatronics Manufacturing and Engineering Non-Destructive Testing Manufacturing and Engineering Non-Destructive Testing Manufacturing and Engineering Engineering - Higher Engineering Trade Manufacturing and Engineering (N.D.T.) Engineering (Non-Destructive Testing) Manufacturing and Engineering Manufacturing Technology Manufacturing and Engineering Mechanical and Manufacturing Engineering Manufacturing and Engineering Mechanical and Manufacturing Engineering Manufacturing and Engineering Manufacturing Technology Manufacturing and Engineering Engineering Manufacturing and Engineering Selected Study Selected Study Program Sponsor Manufacturing and Engineering - Mechanical & Materials (c) 2002 The State of NSW, 11