This document specifies a method and establishes guidelines for non-destructive testing using active thermography with laser excitation. Active thermography with laser excitation is mainly applicable, but not limited, to different materials (e.g. composites, metals, ceramics) and to: – the detection of surface-breaking discontinuities, particularly cracks; – the detection of discontinuities located just below the surface or below coatings with an efficiency that diminishes rapidly with a few mm depth; – the detection of disbonds and delamination parallel to the examined surface; – the measurement of thermal material properties, like thermal diffusivity; – the measurement of coating thickness. The requirements for the equipment, for the verification of the system, for the surface condition of the test object, for the scanning conditions, for the recording, the processing and the interpretation of the results are specified. This document does not apply to the definition of acceptance criteria. Active thermography with laser excitation can be applied in industrial production as well as in maintenance and repair (vehicle parts, engine parts, power plant, aerospace, etc.).<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 4 Qualification and certification of personnel 5 Principle of laser thermography and experimental setup 5.1 General <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 5.2 Typical configurations of excitation 5.2.1 General 5.2.2 Laser thermography in static configuration (without relative movement) 5.2.3 Laser thermography in dynamic configuration (with relative movement) 5.2.4 Laser thermography with different temporal excitations 5.2.5 Laser thermography with different spatial excitations 5.3 Laser and laser optics requirements 5.3.1 Laser irradiance and wavelength <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 5.3.2 Spatial illumination shapes 5.3.2.1 General 5.3.2.2 Spot 5.3.2.3 Straight line 5.3.2.4 Area <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 5.3.2.5 Pattern 5.3.3 Switchable laser for lock-in thermography and other temporal techniques 5.3.4 Safety <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 5.4 Scanning system requirement 5.4.1 General 5.4.2 Test object position and orientation <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 5.4.3 Movement of the test object 5.4.4 Movement of the whole measurement system 5.4.5 Movement of the laser beam through optics 5.4.6 Movement of the laser beam and IR camera through optics 5.4.7 Setup stability 5.5 Specifications of the IR camera <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5.6 Data processing and analysis techniques 5.6.1 General 5.6.2 Spot with relative movement 5.6.2.1 General data evaluation 5.6.2.2 Data analysis by spatial derivative and temporal data sorting <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.6.3 Line with relative movement 5.7 Data processing for crack characterization 5.7.1 General 5.7.2 Static pulsed laser spot <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 5.7.3 Continuously scanned laser spot 5.7.4 Continuously scanned laser line <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.8 Data processing and analysis techniques for the determination of lateral thermal diffusivity 5.9 Data processing and analysis techniques for emissivity correction 5.10 Data processing and analysis techniques for coating thickness control 6 Reference test specimens 7 Calibration, validation and performance of testing <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 8 Evaluation, classification and registration of thermographic indications 9 Test report <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Annex A (informative)List of influential parameters for the NDT qualification of laser thermographic system A.1 General A.2 Input data group parameters A.2.1 Component and his environment: A.2.2 Discontinuities: <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | A.3 NDT laser TT System (procedure parameters) A.3.1 IR Camera and optics <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | A.3.2 Laser A.3.3 Scanning system and set-up A.3.4 Calibration Blocks A.3.5 Data processing and analysis <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Annex B (informative)Reference blocks B.1 Test specimen containing an artificial surface breaking notch <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | B.2 Test specimen containing a natural crack <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | B.3 Test specimen containing natural cracks \u2013 reference block no. 1 for magnetic particle testing according to EN ISO 99342 B.4 Test specimen containing artificial subsurface notches <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Non-destructive testing. Thermographic testing. Active thermography with laser excitation<\/b><\/p>\n |