300+ NDT Level II Interview Questions & Answers (2026) – Practical Guide
 |
| 300+ NDT Level II Interview Questions & Answers (2026) – Practical Guide |
Prepare for NDT Level II interviews with 300+ practical questions and answers covering UT, RT, MT, PT, VT, welding inspection, ASME codes, QA/QC, PAUT, TOFD, ECT and real inspection scenarios.
If you are preparing for an NDT Level II interview, do not focus only on memorizing definitions. Interviewers often test whether you can select a suitable method, verify equipment and calibration, interpret indications, apply the correct acceptance requirement, maintain traceability and respond correctly to practical inspection situations.
This guide covers NDT fundamentals, personnel qualification, VT, PT, MT, UT, RT, PAUT, TOFD, ECT, welding inspection, ASME/QA-QC, practical scenarios and HR questions.
Important Certification Note
ASNT, ISO 9712 and PCN are not interchangeable labels for one universal certification route. Requirements depend on the applicable certification scheme, employer written practice, method, sector and scope. ASNT's current certification information distinguishes general, specific and practical examination components for its Level II routes. Always verify the certification route required by the employer or project.
How to Use This Guide
- Revise the fundamentals first.
- Study the method you are actually certified or experienced in.
- Practice explaining the reason behind your answer, not just the definition.
- Review the applicable code, specification and acceptance criteria for the job.
- Practice the scenario questions aloud before the interview.
Table of Contents
- NDT Fundamentals
- Personnel Qualification & Certification
- Visual Testing (VT)
- Liquid Penetrant Testing (PT)
- Magnetic Particle Testing (MT)
- Ultrasonic Testing (UT)
- Radiographic Testing (RT)
- Welding Inspection & Defects
- ASME, Codes & QA/QC
- PAUT, TOFD & ECT
- Practical Level II Scenarios
- HR & Interview Questions
- Rapid-Fire Revision
NDT Fundamentals
1. What is NDT?
Answer: Non-Destructive Testing is the examination of a material, component or assembly without damaging its intended usefulness.
2. Why is NDT important?
Answer: It helps detect and evaluate discontinuities, supports quality control and helps maintain component safety and reliability.
3. What is a discontinuity?
Answer: An interruption or variation in the normal structure or geometry of a material. A discontinuity is not automatically a rejectable defect.
4. What is a defect?
Answer: A discontinuity that exceeds the applicable acceptance criteria of a code, standard, specification or customer requirement.
5. What is an indication?
Answer: A response or evidence produced by an NDT method that may need interpretation and evaluation.
6. What is a relevant indication?
Answer: An indication caused by a condition or discontinuity that requires evaluation under the applicable procedure.
7. What is a non-relevant indication?
Answer: An indication caused by geometry, material structure or another condition that is not an actionable discontinuity under the applicable procedure.
8. What is a false indication?
Answer: A response that does not represent the condition being sought and is produced by factors such as equipment, technique or surface conditions.
9. What are common NDT methods?
Answer: VT, PT, MT, UT and RT are common methods; ECT, PAUT and TOFD are also widely used for specialized applications.
10. Which methods are mainly used for surface-breaking defects?
Answer: PT is mainly used for surface-breaking discontinuities on suitable non-porous surfaces; MT is used for surface and near-surface discontinuities in ferromagnetic materials.
11. Which methods can detect internal discontinuities?
Answer: UT, RT, PAUT and TOFD can detect internal discontinuities, depending on material, geometry, procedure and defect orientation.
12. Which method uses ionizing radiation?
Answer: Radiographic Testing uses X-rays or gamma radiation and therefore requires appropriate radiation-safety controls.
13. What is sensitivity in NDT?
Answer: The capability of an inspection system and technique to detect relevant discontinuities of a specified size or type.
14. What is resolution?
Answer: The ability of an inspection system to distinguish closely spaced responses as separate indications.
15. What is calibration?
Answer: A controlled comparison or adjustment process used to establish that equipment or a measurement system performs as required by the applicable procedure.
16. What is verification?
Answer: A check confirming that equipment, settings or conditions meet specified requirements before or during examination.
17. What is an NDT procedure?
Answer: A controlled document defining how a particular examination is to be performed, evaluated and recorded.
18. What is an NDT technique?
Answer: The detailed practical implementation of a procedure for a specific component, material, geometry and examination condition.
19. What is an acceptance criterion?
Answer: A defined limit used to decide whether an evaluated indication is acceptable or rejectable.
20. What is traceability?
Answer: The ability to link material, component, weld, examination, personnel, equipment and records through identifiable information.
21. What is QA?
Answer: Quality Assurance is the planned system of processes and controls intended to provide confidence that requirements will be met.
22. What is QC?
Answer: Quality Control is the operational inspection and verification activity used to determine whether specified requirements have been achieved.
23. Why is VT often performed before other NDT?
Answer: It can identify visible surface conditions, weld profile issues, damage and preparation problems before more specialized examinations are performed.
24. Which NDT method is cheapest?
Answer: There is no universal cheapest method; cost depends on geometry, preparation, equipment, personnel, access and project requirements. VT is often low-cost for suitable applications.
25. Which NDT method is best?
Answer: There is no universally best method. Method selection depends on the material, expected discontinuity, location, geometry, access, sensitivity and applicable requirements.
26. What is method selection?
Answer: Choosing an NDT method or combination of methods that can reliably detect and evaluate the discontinuities relevant to the component and service.
27. Why are multiple NDT methods sometimes required?
Answer: Different methods have different physical principles and sensitivities, so combining methods can improve coverage of different discontinuity types and locations.
28. What is examination coverage?
Answer: The portion of the component or weld that is actually examined in accordance with the applicable requirements.
29. What is an inspection report?
Answer: A controlled record documenting what was examined, how it was examined, the applicable criteria and the result.
30. What should an NDT technician never do?
Answer: Never bypass safety controls, alter results, use unqualified personnel for restricted tasks, or accept an indication without applying the applicable procedure and criteria.
Personnel Qualification & Certification
31. What is ASNT?
Answer: ASNT is the American Society for Nondestructive Testing, a professional society that publishes NDT-related standards, recommended practices, training resources and certification information.
32. What is ISO 9712?
Answer: ISO 9712 specifies requirements for the qualification and certification of personnel who perform industrial NDT.
33. What is PCN?
Answer: PCN is a personnel certification scheme associated with BINDT and used for NDT personnel certification.
34. What is Level I?
Answer: Level I personnel generally perform specific tasks under the supervision or direction required by the applicable certification scheme and employer written practice.
35. What is Level II?
Answer: Level II personnel are qualified within their method and scope to perform examinations, interpret and evaluate results, and report them as permitted by the applicable certification scheme and written practice.
36. What is Level III?
Answer: Level III personnel have advanced technical responsibilities such as establishing or approving procedures, interpreting standards and overseeing NDT programs within their certification scope.
37. Is an ASNT document the same as every employer certification?
Answer: No. Certification depends on the applicable scheme, employer written practice and qualification route. The applicable employer and certification requirements must be checked.
38. What is an employer written practice?
Answer: A controlled document defining an employer's requirements for qualification, training, examination, certification, authorization and records of NDT personnel.
39. What is a practical examination?
Answer: An examination in which the candidate demonstrates the ability to perform the relevant NDT method or technique on representative specimens or tasks.
40. What is a specific examination?
Answer: An examination assessing knowledge of the applicable procedures, codes, specifications, equipment and applications for a defined industrial sector or scope.
41. What is a general examination?
Answer: An examination assessing fundamental knowledge and principles of the selected NDT method.
42. Why is visual acuity important?
Answer: NDT personnel need suitable visual capability to correctly perform and interpret examinations within the applicable requirements.
43. Can Level II work without a procedure?
Answer: Not when the applicable certification scheme, written practice, code or contract requires a procedure. The examination must be performed using controlled instructions appropriate to the job.
44. Why should an inspector know the certification scope?
Answer: Because qualification is method-, technique-, sector- and/or employer-scope dependent. Personnel should not perform work outside their authorization.
45. What records should be maintained for NDT personnel?
Answer: Training, experience, examinations, certification, vision records where required, authorization and relevant renewal or recertification records should be controlled according to the applicable scheme.
Visual Testing (VT)
46. What is VT?
Answer: Visual Testing uses direct or aided visual observation to examine surfaces, welds, components and conditions relevant to quality or service.
47. What can VT detect in welds?
Answer: Examples include undercut, overlap, visible cracks, surface porosity, poor profile, arc strikes, excessive reinforcement and dimensional or surface-condition issues.
48. What tools are commonly used in VT?
Answer: Lighting, mirrors, magnifiers, weld gauges, borescopes, cameras and dimensional measuring tools may be used as required.
49. Why is lighting important?
Answer: Adequate lighting improves visibility and helps the inspector reliably detect relevant surface conditions.
50. What is a weld gauge used for?
Answer: It can measure weld dimensions and profile features such as fillet size, reinforcement or undercut, depending on the gauge type.
51. What is remote visual inspection?
Answer: Visual examination performed using optical or electronic equipment when the area cannot be viewed directly.
52. What is a borescope?
Answer: An optical or video instrument used to inspect internal or difficult-to-access areas.
53. Can VT replace UT or RT?
Answer: No. VT cannot detect every internal or subsurface discontinuity and should not be substituted where the applicable requirements call for another method.
54. What is surface preparation for VT?
Answer: The surface should be sufficiently clean and accessible for the required visual examination, as specified by the procedure or acceptance standard.
55. What is a weld profile?
Answer: The shape and contour of the weld face and transition to the adjacent base material.
56. What is undercut?
Answer: A groove or depression at the weld toe or edge that reduces the section of the adjacent base material.
57. What is overlap?
Answer: Weld metal that extends over the base material without proper fusion to it.
58. What is arc strike?
Answer: An unintended localized arc mark on the base material outside the intended weld area.
59. What is weld reinforcement?
Answer: The weld metal projecting beyond the surface of the adjacent base material at the weld face or root, depending on location.
60. What is dimensional inspection?
Answer: Measurement of component or weld dimensions to verify compliance with drawings, specifications and tolerances.
Liquid Penetrant Testing (PT)
61. What is PT?
Answer: PT detects surface-breaking discontinuities by allowing a penetrant to enter an accessible opening and then producing a visible or fluorescent indication.
62. What materials can PT inspect?
Answer: Suitable non-porous materials such as many metals, ceramics and some plastics, provided the surface and penetrant system are compatible.
63. What is the PT principle?
Answer: Capillary action draws penetrant into surface openings; after excess penetrant removal, developer helps draw penetrant back out to form an indication.
64. What are the basic PT steps?
Answer: Pre-clean, apply penetrant, allow dwell, remove excess penetrant, apply developer, inspect and post-clean when required.
65. Why is pre-cleaning important?
Answer: Contamination can block discontinuities, interfere with penetrant action or create misleading indications.
66. What is penetrant dwell time?
Answer: The specified time allowed for penetrant to enter relevant surface openings.
67. What happens if dwell time is too short?
Answer: Small or tight discontinuities may not develop adequate indications.
68. What happens if excess penetrant is not removed correctly?
Answer: Background can become excessive and obscure or create misleading indications.
69. What is developer?
Answer: A material that helps draw trapped penetrant from surface discontinuities and provides a contrasting background.
70. What is fluorescent PT?
Answer: A PT system using fluorescent penetrant viewed under the specified ultraviolet/appropriate inspection conditions.
71. What is visible dye PT?
Answer: A PT system using a visible contrasting dye, typically evaluated under suitable white-light conditions.
72. What is bleed-out?
Answer: The visible or fluorescent emergence of penetrant from a surface discontinuity during development.
73. What is a linear indication?
Answer: An indication whose length is significantly greater than its width; the applicable standard determines how it is classified and accepted.
74. What is a rounded indication?
Answer: An indication whose length and width are more similar, subject to the definitions of the applicable standard.
75. Can PT detect subsurface defects?
Answer: Normally no. PT requires the discontinuity to be open to the surface.
76. Why is post-cleaning performed?
Answer: To remove residual chemicals when required for subsequent processing, service, corrosion control or product cleanliness.
77. What causes background fluorescence?
Answer: Residual penetrant, contamination, excessive penetrant removal problems or unsuitable conditions can contribute to background.
78. Can PT be performed on porous surfaces?
Answer: Generally PT is unsuitable for highly porous surfaces because penetrant can be trapped throughout the material and create excessive background.
79. What is the main limitation of PT?
Answer: It detects only discontinuities open to the surface and requires a suitable, accessible, reasonably non-porous surface.
80. What safety precautions are important in PT?
Answer: Follow chemical SDS requirements, ventilation, PPE, UV/lighting precautions where applicable, fire controls and the approved procedure.
Magnetic Particle Testing (MT)
81. What is MT?
Answer: MT detects surface and near-surface discontinuities in ferromagnetic materials by magnetizing the part and observing magnetic-particle accumulation at leakage fields.
82. What materials are suitable for MT?
Answer: Ferromagnetic materials such as many carbon and low-alloy steels and some ferromagnetic cast irons.
83. Can stainless steel be tested by MT?
Answer: Only ferromagnetic stainless grades are suitable. Austenitic stainless steels are generally non-ferromagnetic and are not suitable for conventional MT.
84. What is magnetic flux?
Answer: Magnetic field flow through a magnetized material.
85. What is flux leakage?
Answer: A local disturbance of the magnetic field caused by a discontinuity, which can attract magnetic particles.
86. Why should the magnetic field be oriented properly?
Answer: Discontinuities are most detectable when their orientation produces a strong leakage field, typically near perpendicular to the applied magnetic field.
87. What is the yoke method?
Answer: A magnetic yoke creates a localized magnetic field between its poles and is commonly used for surface crack detection.
88. What is the coil method?
Answer: A coil creates a longitudinal magnetic field in a component positioned within or near the coil.
89. What is the prod technique?
Answer: Current is introduced through contact points to create a local magnetic field; appropriate controls are needed to avoid arc burns.
90. What is wet MT?
Answer: Magnetic particles are suspended in a liquid carrier and applied to the magnetized area.
91. What is dry MT?
Answer: Dry magnetic particles are applied to a magnetized surface.
92. What is visible MT?
Answer: Visible colored particles are evaluated under suitable white light.
93. What is fluorescent MT?
Answer: Fluorescent particles are evaluated under the specified UV-A/appropriate inspection conditions.
94. Why is demagnetization sometimes required?
Answer: Residual magnetism can interfere with later operations, instrumentation, welding or service requirements.
95. What is residual magnetism?
Answer: Magnetism remaining in the component after the magnetizing force is removed.
96. Can MT detect deep internal defects?
Answer: MT is primarily a surface and near-surface method; it is not a substitute for volumetric methods for deep internal discontinuities.
97. Why is surface cleaning important?
Answer: Heavy scale, paint, dirt or other contamination can reduce sensitivity or interfere with particle movement and interpretation.
98. What is a relevant MT indication?
Answer: A particle accumulation caused by a discontinuity or condition that requires evaluation under the procedure.
99. What can cause non-relevant MT indications?
Answer: Geometry changes, keyways, sharp corners, permeability variations and other magnetic-field disturbances can produce non-relevant indications.
100. What is the main limitation of MT?
Answer: The material must be sufficiently ferromagnetic and the method has limited depth capability compared with volumetric methods.
Ultrasonic Testing (UT)
101. What is UT?
Answer: UT uses high-frequency sound waves to examine material and detect or characterize internal or surface-connected discontinuities.
102. What is a transducer?
Answer: A device that converts electrical energy to ultrasonic energy and/or receives ultrasonic energy and converts it back to an electrical signal.
103. What is a probe?
Answer: The ultrasonic search unit used to transmit and receive sound in the component.
104. What is couplant?
Answer: A material placed between the probe and test surface to provide efficient transmission of ultrasonic energy.
105. Why is couplant required?
Answer: Air between the probe and component strongly reduces ultrasonic transmission, so couplant provides an effective acoustic path.
106. What is straight-beam UT?
Answer: A technique using predominantly longitudinal waves normal to the surface, commonly used for thickness measurement and lamination detection.
107. What is angle-beam UT?
Answer: A technique that introduces an angled sound beam into the component, commonly used for weld examination.
108. What is a shear wave?
Answer: A wave in which particle motion is primarily perpendicular to the direction of propagation.
109. What is a longitudinal wave?
Answer: A wave in which particle motion is primarily parallel to the direction of propagation.
110. What is sound velocity?
Answer: The speed at which the ultrasonic wave travels through a particular material and wave mode.
111. What affects sound velocity?
Answer: Material properties, temperature, wave mode and composition can affect the applicable velocity.
112. What is frequency?
Answer: The number of wave cycles per unit time, commonly expressed in MHz for ultrasonic testing.
113. What is wavelength?
Answer: The physical distance between corresponding points of successive wave cycles.
114. What happens to wavelength when frequency increases?
Answer: For a fixed material velocity, wavelength decreases as frequency increases.
115. What is near field?
Answer: The region close to the transducer in which the sound field has complex interference and amplitude variations.
116. What is far field?
Answer: The region beyond the near field where the sound beam generally diverges and its characteristics are more predictable.
117. What is beam spread?
Answer: The angular divergence of the ultrasonic beam as it travels through the material.
118. What is attenuation?
Answer: Loss of ultrasonic energy as sound travels through material due to absorption and scattering.
119. What is DAC?
Answer: Distance-Amplitude Correction is a reference curve used to relate echo amplitude to distance for evaluation within the applicable procedure.
120. What is TCG?
Answer: Time-Corrected Gain is an electronic gain compensation method that adjusts gain with time/distance so equivalent reflectors can be displayed at a more uniform amplitude.
121. What is a calibration block?
Answer: A reference block used to establish or verify instrument settings and/or sensitivity as required by the procedure.
122. What is a reference block?
Answer: A block containing known geometry or reflectors used to set up or verify an examination system.
123. What is back-wall echo?
Answer: The ultrasonic response from the far boundary of the test piece.
124. What can cause loss of back-wall echo?
Answer: Attenuation, roughness, geometry, poor coupling, misalignment or a discontinuity can reduce or eliminate the back-wall response.
125. What is probe index point?
Answer: The point on an angle-beam probe used as the reference for calculating or measuring sound-path geometry.
126. What is skip distance?
Answer: The surface distance associated with a sound beam traveling through a complete skip path in a component, based on the beam angle and geometry.
127. What is half-skip?
Answer: A sound path from the entry surface to the opposite surface or other reference boundary before the beam returns toward the original surface, depending on geometry.
128. What is sound path?
Answer: The distance traveled by the ultrasonic beam along its acoustic path.
129. What is depth estimation?
Answer: Determining the approximate location of a reflector using calibrated sound path, probe angle, geometry and the applicable technique.
130. What is transfer correction?
Answer: An adjustment made to account for differences between the calibration/reference condition and the actual test surface or component.
131. Why is scanning coverage important?
Answer: The probe must cover the required examination volume from suitable directions so relevant discontinuities are not missed.
132. What is a dead zone?
Answer: A region near the probe where receiver recovery and initial pulse effects can make small reflectors difficult to detect.
133. What is resolution in UT?
Answer: The ability to separate and identify closely spaced reflectors or responses.
134. What is sensitivity setting?
Answer: The instrument gain or related setup used to make the required reference reflector detectable at the specified level.
135. Why should probe movement be controlled?
Answer: Controlled scanning speed, overlap and indexing help ensure consistent examination coverage.
136. Can UT detect every defect?
Answer: No. Detectability depends on discontinuity orientation, size, location, material, geometry, surface condition, frequency and procedure.
137. Why is calibration checked before and after examination?
Answer: To verify that the system remains within the required setup and performance conditions.
138. What is a linear indication in UT?
Answer: A response interpreted as potentially associated with a planar or elongated discontinuity; it must be evaluated according to the applicable procedure.
139. What is the difference between UT thickness measurement and weld UT?
Answer: Thickness measurement commonly uses a simpler pulse-echo setup, while weld UT may require angle beams, scanning patterns, reference levels and specific evaluation rules.
140. What is the role of the written UT procedure?
Answer: It defines the equipment, probe, calibration, scanning, sensitivity, coverage, evaluation and recording requirements for the specific examination.
Radiographic Testing (RT)
141. What is RT?
Answer: Radiographic Testing uses X-rays or gamma rays to create an image showing variations in material attenuation.
142. What is the basic RT principle?
Answer: Different thicknesses, densities and discontinuities attenuate radiation differently, producing image contrast that can reveal internal conditions.
143. What is the difference between X-ray and gamma radiography?
Answer: X-rays are generated electrically; gamma radiation is emitted by radioactive isotopes.
144. Why is radiation safety critical?
Answer: Ionizing radiation can harm people, so exposure must be controlled using time, distance, shielding, barriers and applicable regulations.
145. What is SFD?
Answer: Source-to-film distance, or the corresponding source-to-detector distance in digital systems, is a geometric setup parameter affecting image quality.
146. What is geometric unsharpness?
Answer: Image blur caused by the finite source size and geometric arrangement of source, object and detector/film.
147. What affects geometric unsharpness?
Answer: Source size, object-to-detector distance and source-to-object distance are key factors.
148. What is IQI?
Answer: An Image Quality Indicator is a device used to demonstrate the required radiographic image quality or sensitivity.
149. Why is an IQI used?
Answer: It provides evidence that the radiographic technique has achieved the required image quality for the applicable procedure or standard.
150. What is radiographic density?
Answer: A measure of the degree to which a radiographic film image attenuates transmitted viewing light; digital systems use different image-display concepts.
151. What is contrast?
Answer: The difference in image response between adjacent areas; it is influenced by subject contrast and detector/film characteristics.
152. What is exposure time?
Answer: The duration for which the test object is exposed to the radiation source under the selected technique.
153. What happens with insufficient exposure?
Answer: The image may have inadequate density or signal-to-noise/contrast characteristics and may fail the applicable image-quality requirements.
154. What is film processing?
Answer: For film radiography, chemical processing develops, fixes, washes and dries the film to produce the radiographic image.
155. What is a radiographic interpreter?
Answer: A qualified person who interprets radiographic images within the scope of the applicable certification, procedure and employer requirements.
156. What is a radiographic technique sheet?
Answer: A controlled record describing the selected RT setup, source, geometry, exposure and image-quality parameters.
157. What is double-wall single-image technique?
Answer: A technique in which radiation passes through two walls but the radiographic image is intended to show one wall or relevant image separately, depending on geometry.
158. What is single-wall single-image technique?
Answer: Radiation passes through one wall and the image of that wall is recorded on the detector/film.
159. What is double-wall double-image technique?
Answer: A technique where both walls of a component may be projected onto the same radiograph, commonly used for small-diameter piping under applicable requirements.
160. What is a penetrameter?
Answer: Another common term for an IQI used to demonstrate radiographic sensitivity.
161. What are common RT weld indications?
Answer: Porosity, slag inclusions, lack of fusion, incomplete penetration and cracks may be encountered, subject to the material and welding process.
162. Can RT detect planar defects reliably?
Answer: Detectability depends strongly on defect orientation relative to the radiation beam; planar defects can be difficult when oriented unfavorably.
163. What is radiation exclusion zone?
Answer: A controlled area established to prevent unauthorized personnel from entering a radiation exposure area.
164. What is a survey meter?
Answer: An instrument used to measure radiation dose rate or related radiation levels for safety control.
165. What is a dosimeter?
Answer: A device used to monitor an individual's radiation exposure according to applicable radiation-safety requirements.
166. What is source strength?
Answer: The activity or output characteristic of the radiation source used to determine exposure capability and technique requirements.
167. What is source decay?
Answer: Radioactive sources generally decrease in activity with time, changing the exposure conditions required to obtain the desired radiographic result.
168. What is a gamma projector?
Answer: A device designed to safely transport, store and expose a sealed radioactive source in accordance with applicable regulations and procedures.
169. What is the first action if a radiation safety alarm indicates a problem?
Answer: Follow the approved radiation-safety procedure, stop or secure the exposure as safely as possible, maintain the exclusion zone and notify the responsible radiation-safety personnel.
170. What is RT acceptance criteria?
Answer: The applicable acceptance criteria are defined by the governing construction code, specification or standard; the RT method itself does not automatically define acceptance.
171. Why should Section V and Section VIII not be confused?
Answer: Section V generally contains NDE method requirements, while Section VIII may contain construction-code requirements including when and how examinations and acceptance are applied to pressure vessels.
172. What is spot radiography?
Answer: A sampling-based radiographic examination performed at specified locations in accordance with the applicable construction-code requirements.
173. What is full radiographic examination?
Answer: Radiographic examination performed to the extent required by the applicable construction-code provisions; the exact extent must be verified from the governing requirements.
174. What is film artifact?
Answer: An unwanted mark or image caused by handling, processing, equipment, dirt, scratches or other factors rather than the component condition.
175. How should a suspected artifact be handled?
Answer: Verify the indication using the applicable procedure and, where necessary, repeat the examination rather than accepting or rejecting the weld based on an unverified artifact.
176. Why is identification marking important?
Answer: It provides traceability between the image and the component, weld and examination record.
177. What should be checked before interpreting an RT image?
Answer: Verify identification, image quality, required sensitivity, applicable technique, coverage and image condition before evaluating indications.
178. What is the biggest RT safety mistake?
Answer: Entering a controlled radiation area or approaching a source without following the approved radiation-safety controls.
179. What should an RT report contain?
Answer: At minimum, the required component/weld identification, technique information, procedure, personnel, examination result and relevant acceptance/disposition information required by the governing documents.
Welding Inspection & Defects
180. What is a weld discontinuity?
Answer: An interruption or irregularity in the weld or adjacent material that may or may not be acceptable.
181. Name common weld defects.
Answer: Cracks, lack of fusion, incomplete penetration, slag inclusion, porosity, undercut, overlap, excessive reinforcement and arc strikes are common examples.
182. What causes lack of fusion?
Answer: Insufficient heat input, incorrect technique, poor joint preparation, contamination, incorrect travel angle or inadequate interpass control can contribute.
183. What causes incomplete penetration?
Answer: Improper root gap, inadequate root preparation, low heat input, incorrect electrode size or technique can contribute.
184. What causes porosity?
Answer: Hydrogen/moisture, contamination, shielding problems, excessive arc length or unsuitable welding conditions can contribute.
185. What causes slag inclusion?
Answer: Poor cleaning between passes, incorrect manipulation, unsuitable current or electrode angle and unfavorable joint geometry can contribute.
186. What causes undercut?
Answer: Excessive current, high travel speed, incorrect electrode angle or poor technique can contribute.
187. What causes overlap?
Answer: Excessive deposition, low travel speed, incorrect angle or poor control can contribute.
188. What causes cracks?
Answer: Hydrogen, restraint, unsuitable thermal conditions, metallurgical effects, high stresses and unsuitable welding procedure variables can contribute.
189. What is crater cracking?
Answer: Cracking that can occur in the weld crater when the weld is terminated improperly or conditions promote shrinkage cracking.
190. What is hot cracking?
Answer: Cracking that occurs at elevated temperature during solidification or shortly afterward, often associated with metallurgical composition and restraint.
191. What is cold cracking?
Answer: Cracking that occurs after cooling, often associated with hydrogen, hard microstructure and residual stress.
192. What is hydrogen cracking?
Answer: A delayed cracking mechanism involving diffusible hydrogen, susceptible microstructure and tensile stress.
193. What is preheating?
Answer: Heating the base material before welding to control cooling rate, reduce thermal gradients and help meet the welding procedure requirements.
194. What is interpass temperature?
Answer: The temperature of the weld area immediately before depositing the next weld pass, controlled within the applicable WPS range.
195. What is PWHT?
Answer: Post Weld Heat Treatment is controlled heating and cooling after welding for purposes such as stress relief or metallurgical control when required by the governing requirements.
196. What is WPS?
Answer: A Welding Procedure Specification gives the welding variables and requirements used to produce welds under controlled conditions.
197. What is PQR?
Answer: A Procedure Qualification Record documents the actual variables and test results used to qualify a welding procedure.
198. What is WPQ/WQTR?
Answer: A welder or welding operator qualification record documents qualification of the individual for specified welding variables and ranges.
199. What is a weld map?
Answer: A controlled drawing or record identifying weld locations and related traceability information.
200. What is weld traceability?
Answer: The ability to link a weld to the joint, materials, welder, WPS, consumables, NDT and inspection records.
201. What is fit-up inspection?
Answer: Inspection of joint preparation, alignment, root gap, mismatch, cleanliness and dimensions before welding.
202. Why is root gap important?
Answer: It affects penetration, root geometry and compliance with the qualified welding procedure.
203. What is hi-lo?
Answer: Internal misalignment between components at a joint, especially common in pipe fit-up.
204. Why is interpass cleaning important?
Answer: It removes slag and contamination and helps prevent inclusions and lack of fusion between passes.
205. What is weld visual acceptance?
Answer: A decision based on measured weld features and visible discontinuities against the applicable drawing, code or specification.
206. Why should arc strikes be repaired when required?
Answer: They can create localized metallurgical changes or cracking and may be prohibited by the governing specification.
207. What is weld reinforcement?
Answer: Weld metal extending beyond the adjacent base-metal surface at the weld face or root.
208. What is root concavity?
Answer: A condition where the weld surface at the root is recessed below the adjacent base-metal surface.
209. What is burn-through?
Answer: Excessive melting or penetration that produces a hole or severe root collapse during welding.
210. What is a weld repair?
Answer: Controlled removal and replacement of unacceptable weld metal followed by the required inspection and documentation.
211. What should be checked after weld repair?
Answer: Verify repair procedure, excavation, welding variables, consumables, traceability and required NDT/re-examination.
212. Why is material traceability important before welding?
Answer: It confirms that the correct material grade and condition are being used and links the material to its certificates and manufacturing records.
213. What is PMI?
Answer: Positive Material Identification is a method of verifying material composition or grade, commonly using portable analytical techniques.
214. What is a consumable certificate?
Answer: A document providing identification and specified properties or compliance information for welding consumables, as required.
215. Why is electrode storage important?
Answer: Moisture and improper storage can affect consumable performance and may increase hydrogen-related risk for applicable electrodes.
216. What is a heat number?
Answer: A traceability identifier assigned to a material heat or batch and recorded on material certificates and manufacturing records.
217. What is ITP?
Answer: Inspection and Test Plan defining inspection stages, responsibilities, hold/witness points and required records.
218. What is QAP?
Answer: Quality Assurance Plan or Quality Assurance/Inspection Plan defining project quality controls and verification requirements.
ASME, Codes & QA/QC
219. What is ASME Section V?
Answer: ASME BPVC Section V contains requirements and methods for nondestructive examination used within the applicable ASME framework.
220. What is ASME Section VIII Division 1?
Answer: A pressure-vessel construction code containing requirements for design, fabrication, examination, inspection and testing within its scope.
221. What is ASME Section IX?
Answer: A code section covering qualification of welding, brazing and related joining procedures and personnel within its scope.
222. What is ASME Section II?
Answer: A section containing material specifications and related material requirements within the ASME Boiler and Pressure Vessel Code.
223. What is a code requirement?
Answer: A mandatory requirement when the code is contractually or legally applicable to the work.
224. What is a project specification?
Answer: A project-specific document adding requirements, clarifications or acceptance provisions beyond or alongside the governing code.
225. Which document controls acceptance?
Answer: The applicable contract/code/specification and approved inspection documentation determine the acceptance criteria; the inspector must identify the governing requirement.
226. What is an ITP hold point?
Answer: A stage at which work cannot proceed until the designated party completes the required inspection/release.
227. What is a witness point?
Answer: A point where the designated party is notified and may witness the activity according to the ITP; the exact release rule depends on the project.
228. What is an NCR?
Answer: A Non-Conformance Report documenting a condition that does not meet specified requirements.
229. What is CAPA?
Answer: Corrective and Preventive Action is a structured process for addressing causes of nonconformities and reducing recurrence risk.
230. What is root-cause analysis?
Answer: A systematic investigation to identify underlying causes rather than only treating the immediate symptom.
231. What is calibration status?
Answer: The documented condition showing whether measuring or inspection equipment is within its required calibration/verification validity.
232. What is document control?
Answer: A system ensuring that approved revisions are available for use and obsolete or uncontrolled documents are prevented from unintended use.
233. What is material test certificate (MTC)?
Answer: A controlled material certificate providing specified chemical, mechanical and/or manufacturing information and traceability.
234. What is heat treatment chart review?
Answer: Verification that recorded heating, soaking and cooling conditions meet the applicable procedure and requirements.
235. What is hydrostatic testing?
Answer: A pressure test using a liquid, commonly water, to demonstrate pressure integrity according to the governing requirements.
236. What is pneumatic testing?
Answer: A pressure test using a gas; it generally involves higher stored-energy risk and requires strict safety controls.
237. What is dimensional inspection?
Answer: Verification of dimensions, geometry, alignment and tolerances against drawings and specifications.
238. What is punch-list clearance?
Answer: The controlled closure and verification of outstanding inspection or quality items before final release.
239. What is final dossier?
Answer: A compiled set of project quality records such as certificates, inspection reports, NDT reports, weld records, test records and approvals.
240. Why is traceability important in QA/QC?
Answer: It allows every inspection result and material/component to be linked to its source, process and final disposition.
241. What is an inspection release note?
Answer: A controlled document confirming release of a component or stage after required inspections are completed.
242. What is client/TPI inspection?
Answer: Inspection or witnessing performed by the customer or an independent third-party inspection agency according to the agreed inspection plan.
243. What is an authorized inspector?
Answer: A person recognized under the applicable code/regulatory framework to perform specified inspection duties within that scope.
244. What is a deviation?
Answer: A formally controlled departure from a specified requirement, approved by the authorized parties where permitted.
245. What is concession?
Answer: A documented acceptance of a nonconforming condition by an authorized party when the governing requirements permit such disposition.
246. What is a quality objective?
Answer: A measurable quality target established to support consistent project performance and compliance.
247. Why is inspection planning important?
Answer: It ensures the correct methods, personnel, procedures, acceptance criteria and records are available at the correct manufacturing stages.
248. What is final acceptance?
Answer: A formal decision that the component or work package meets all applicable requirements and has the required records and approvals.
PAUT, TOFD & ECT
249. What is PAUT?
Answer: Phased Array Ultrasonic Testing uses multiple transducer elements whose timing is controlled electronically to steer and focus the ultrasonic beam.
250. What is beam steering in PAUT?
Answer: Electronic control of element firing delays to direct the beam at selected angles.
251. What is focusing in PAUT?
Answer: Controlling element delays to concentrate acoustic energy at a selected depth or region.
252. What is an S-scan?
Answer: A sectorial scan display showing responses obtained over a range of beam angles.
253. What is an A-scan?
Answer: A display of signal amplitude versus time or sound path.
254. What is a C-scan?
Answer: A plan-view style display showing responses or mapped information across an area.
255. What is an encoded scan?
Answer: A scan in which probe position is recorded along with ultrasonic data to produce a spatially referenced result.
256. What is PAUT calibration?
Answer: Verification and adjustment of the PAUT system using the applicable reference block and procedure for parameters such as velocity, wedge delay and sensitivity.
257. What is TOFD?
Answer: Time of Flight Diffraction is an ultrasonic technique that uses diffracted signals from the tips of planar discontinuities for detection and sizing.
258. Why is TOFD useful for weld inspection?
Answer: It can provide accurate through-wall sizing of suitable planar indications and offers recorded inspection data.
259. What are TOFD probes?
Answer: Typically a pair of angle-beam probes arranged on opposite sides of a weld so that diffracted signals can be received.
260. What is a TOFD lateral wave?
Answer: A signal traveling near the surface between the probes and used as a reference in TOFD interpretation.
261. What is a TOFD back-wall signal?
Answer: A signal from the far surface of the component that helps establish geometry and reference conditions.
262. What is a TOFD dead zone?
Answer: A near-surface region where reliable detection or sizing may be limited by the lateral wave, probe configuration and other effects.
263. Can TOFD detect every flaw?
Answer: No. Orientation, size, location, geometry and near-surface limitations affect detectability.
264. What is ECT?
Answer: Eddy Current Testing uses electromagnetic induction to detect changes associated with material properties, geometry and discontinuities in electrically conductive materials.
265. What materials are suitable for ECT?
Answer: Electrically conductive materials are suitable, including many metals.
266. What is lift-off in ECT?
Answer: A change in probe-to-surface distance that alters the eddy-current response.
267. What is conductivity in ECT?
Answer: A material property affecting how eddy currents are induced and distributed.
268. What is skin effect?
Answer: The tendency of alternating current to concentrate near the surface, with effective penetration decreasing as frequency increases.
269. What affects ECT penetration?
Answer: Frequency, conductivity, permeability and material properties affect penetration depth.
270. What is remote field testing?
Answer: An electromagnetic inspection technique commonly used for ferromagnetic tubes where the field travels through and around the tube wall to detect discontinuities.
271. Why is ECT useful for tubes?
Answer: It can inspect conductive tubing rapidly and detect certain surface and subsurface conditions without direct access to the entire outer surface.
272. What is impedance-plane display?
Answer: A display representing the phase and amplitude characteristics of an eddy-current signal, useful for separating response types.
273. What is probe calibration in ECT?
Answer: Setup and verification using suitable reference standards containing known artificial or natural indications.
Practical Level II Scenarios
274. A UT calibration is lost during scanning. What do you do?
Answer: Stop the examination, restore and verify calibration according to the procedure, determine the affected scan interval and repeat examinations where required.
275. You find a crack during inspection. What is your first step?
Answer: Verify the indication and its characterization, then apply the governing acceptance criteria and document the finding before disposition.
276. A client asks you to accept a rejectable indication. What do you do?
Answer: Do not change the result. Explain the applicable requirement and escalate through the defined quality and client communication process.
277. The drawing and specification give different requirements. What do you do?
Answer: Stop and obtain formal clarification from the responsible engineering/quality authority; do not choose the less restrictive requirement yourself.
278. The NDT procedure is expired or uncontrolled. Can you continue?
Answer: No. Use only the current approved procedure required for the examination.
279. Your equipment calibration has expired. Can you inspect?
Answer: Not unless the governing procedure explicitly permits a controlled verification or other defined action. Normally the equipment must be within required calibration status.
280. The surface is heavily contaminated before PT. What do you do?
Answer: Stop and clean the surface according to the procedure before examination.
281. MT shows a strong indication at a sharp corner. Is it automatically a crack?
Answer: No. Geometry can produce non-relevant indications. Verify the response using the applicable technique and evaluation procedure.
282. RT shows an unusual mark. What should you do?
Answer: Check whether it is an artifact, image-quality issue or component indication; verify using the applicable technique before making a disposition.
283. A weld fails VT. Can you perform UT anyway?
Answer: Follow the ITP and procedure. A failed prerequisite may need correction before further NDT, depending on the governing requirements.
284. A repair has been completed. What next?
Answer: Verify repair records and perform the required visual and NDT re-examination using the applicable procedure and acceptance criteria.
285. A welder changes a variable outside the qualified WPS range. What do you do?
Answer: Stop or place the work on hold as appropriate and obtain review by the welding/quality authority before continuing.
286. Material heat number is missing. Can you accept the component?
Answer: Do not assume traceability. Place the item on hold and restore or formally resolve traceability according to the quality system.
287. A client requests a verbal acceptance only. What do you do?
Answer: Provide the required controlled inspection record; acceptance should be traceable and documented.
288. A technician asks you to sign a report for work you did not perform or review. What do you do?
Answer: Do not sign inaccurately. Sign only records for which you have the required responsibility and knowledge.
289. An RT exclusion zone is not secure. What do you do?
Answer: Do not proceed with exposure. Secure the area according to the radiation-safety procedure before continuing.
290. The inspection surface is inaccessible. What do you do?
Answer: Determine whether an approved alternative technique or access arrangement can satisfy the examination requirements; do not improvise outside the procedure.
291. The indication is close to the acceptance limit. What should you do?
Answer: Measure carefully, verify calibration and image/scan quality, review the complete applicable acceptance criteria and document the basis for the decision.
292. You find repeated defects from the same welding team. What should you do?
Answer: Record the nonconformities, notify the responsible quality/welding personnel and support root-cause and corrective-action review.
293. Production asks you to speed up the inspection by reducing coverage. What do you do?
Answer: Do not reduce required coverage. Explain the requirement and escalate the schedule issue through management.
294. A Level I technician asks you to interpret a complex indication. What do you do?
Answer: Provide supervision and perform or verify the interpretation within your certification and employer scope.
295. You are unsure which acceptance criterion applies. What do you do?
Answer: Stop the acceptance decision and identify the governing code, specification, drawing and approved procedure before proceeding.
296. The calibration block is damaged. Can it be used?
Answer: Only if the applicable procedure permits it and the block still meets its required condition; otherwise replace or formally evaluate it.
297. A client disputes your reject. What evidence should you show?
Answer: Show the relevant report, indication measurements, calibration/image-quality records, procedure and applicable acceptance requirement.
298. An NDT report has the wrong weld number. What do you do?
Answer: Correct the record using the controlled document-correction process and ensure traceability is restored.
299. You discover an earlier report was incorrectly accepted. What do you do?
Answer: Notify the responsible quality authority, preserve the original record, initiate controlled correction and determine whether re-examination is required.
300. A component has a coating before MT/PT. What do you do?
Answer: Verify whether the coating is compatible with the required sensitivity and procedure; remove or prepare it if required.
301. A UT indication changes dramatically with probe movement. What could it mean?
Answer: It may be affected by geometry, orientation, coupling or a real discontinuity. Evaluate it systematically using the approved scanning and characterization method.
302. A customer asks for an inspection outside your certification scope. What do you do?
Answer: Decline or arrange qualified personnel; never perform work outside your authorization.
303. How do you prioritize multiple inspection requests?
Answer: Follow safety and hold points first, then production priorities and scheduled examinations while maintaining required coverage and documentation.
HR & Interview Questions
304. Tell me about yourself.
Answer: Give a 60–90 second summary covering education, certifications, methods, industries, major responsibilities and the type of role you are targeting.
305. Why did you choose NDT?
Answer: Explain your interest in inspection, problem solving, engineering reliability and the opportunity to work close to manufacturing quality.
306. Why should we hire you as an NDT Level II?
Answer: Connect your certification, practical inspection experience, code knowledge, safety discipline, reporting ability and problem-solving skills to the employer's requirements.
307. What are your strongest NDT methods?
Answer: Name the methods you are actually certified and experienced in, then give one practical example for each.
308. What is your biggest technical strength?
Answer: Choose a genuine strength such as weld evaluation, UT calibration, RT interpretation, procedure compliance or inspection documentation and support it with an example.
309. What is your weakness?
Answer: Choose a manageable weakness and explain the specific action you are taking to improve it.
310. How do you handle pressure?
Answer: Prioritize safety and mandatory inspection requirements, communicate clearly and organize the work rather than skipping controls.
311. How do you handle a production-quality conflict?
Answer: Use objective evidence, the approved procedure and applicable acceptance criteria, then escalate the issue through the defined quality process.
312. Tell me about a difficult defect you found.
Answer: Explain the component, method, indication, evaluation, action and final result without exaggerating your role.
313. How do you handle a failed inspection?
Answer: Record the result objectively, identify the requirement, communicate the nonconformance and follow the repair/re-examination process.
314. How do you deal with a difficult supervisor?
Answer: Remain professional, communicate facts and requirements clearly and use the formal escalation route when necessary.
315. Are you comfortable with documentation?
Answer: Yes; explain the reports, traceability records, calibration records, NDT reports and inspection dossiers you have handled.
316. Are you comfortable working on site?
Answer: State your actual availability and experience honestly, including shifts, travel or site conditions you can accept.
317. How do you ensure safety during NDT?
Answer: Follow the method-specific safety procedure, PPE requirements, permits, exclusion controls and equipment checks.
318. Where do you see yourself in five years?
Answer: Describe a realistic path such as senior inspection responsibility, Level III development, QA/QC leadership or specialist NDT expertise.
319. Why are you leaving your current company?
Answer: Keep the answer professional: explain that you are looking for greater responsibility, technical exposure, growth or a better-aligned role rather than criticizing your employer.
320. What salary do you expect?
Answer: Give a reasonable range based on your experience and the total compensation structure, while remaining open to discussing the complete role and benefits.
321. Can you work overtime?
Answer: Answer honestly and emphasize that safety and inspection quality should not be compromised by schedule pressure.
322. How do you handle mistakes?
Answer: Report them promptly, correct the record through controlled processes and identify the cause so the mistake is not repeated.
323. What makes a good NDT Level II?
Answer: Technical knowledge, method competence, disciplined procedure use, accurate interpretation, safety awareness, traceability and professional integrity.
Rapid-Fire Revision
324. What is PT best at?
Answer: Detecting accessible surface-breaking discontinuities on suitable non-porous materials.
325. What is MT best at?
Answer: Detecting surface and near-surface discontinuities in suitable ferromagnetic materials.
326. What is UT best at?
Answer: Detecting and evaluating many internal discontinuities and measuring thickness using suitable procedures.
327. What is RT best at?
Answer: Producing an image of internal material variations and discontinuities based on radiation attenuation.
328. What is VT best at?
Answer: Fast detection of visible surface and dimensional conditions.
329. What is PAUT best at?
Answer: Electronically controlled ultrasonic beam steering and recording for suitable applications.
330. What is TOFD best at?
Answer: Detection and sizing of suitable planar discontinuities using diffracted signals.
331. What is ECT best at?
Answer: Detecting and characterizing certain conditions in electrically conductive materials using electromagnetic induction.
332. What is a hold point?
Answer: A mandatory inspection or approval stage before work proceeds.
333. What is a witness point?
Answer: A notified inspection stage where the designated party may witness according to the agreed inspection plan.
334. What is an NCR?
Answer: A controlled record of nonconformance against a specified requirement.
335. What is a repair procedure?
Answer: An approved instruction defining how an unacceptable condition is to be removed, repaired and re-examined.
336. What is a calibration record?
Answer: Evidence that equipment was checked or calibrated according to the applicable requirements.
337. What is a weld map?
Answer: A traceability record identifying weld locations and associated information.
338. What is a material certificate?
Answer: A controlled record showing specified material information and traceability.
339. What is a WPS?
Answer: A controlled welding instruction specifying qualified welding variables and requirements.
340. What is a PQR?
Answer: A record of the actual variables and qualification test results used to support a welding procedure qualification.
341. What is WPQ?
Answer: A record showing qualification of a welder or welding operator within defined variables and ranges.
342. What is an ITP?
Answer: A plan identifying inspection and testing activities, responsibilities and required intervention points.
343. What is an inspection dossier?
Answer: The compiled set of quality and inspection records required for final project handover.
Final Interview Advice
The strongest Level II candidate is not the person who memorizes the most definitions. It is the candidate who can explain a practical inspection decision logically:
- Identify the component and examination requirement.
- Check the applicable procedure, code and specification.
- Verify equipment, calibration and examination conditions.
- Perform the examination with the required coverage.
- Characterize and measure the indication correctly.
- Apply the correct acceptance criteria.
- Document the result and control any repair or re-examination.
Related NDT Guides
- Complete NDT Learning Hub – 2026 Guide
- ASME Section VIII RT Acceptance Criteria: UW-51 vs UW-52
- Visual Testing (VT) Complete Guide
- TOFD Guide
- Eddy Current Testing (ECT) Guide
NDTQualityHub — Practical NDT, Welding Inspection and Quality Engineering Knowledge.
.png)
Hello readers , hope u enjoying reading our blogs and this will help you to gain basic to advance level knowledge about NDT. please write & share a suggestion and your experience with us in comment section. so we can deliver more about your prefer topics..
ReplyDelete