Liquid Penetrant Testing Process Flashcards
7 cards from real NDT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Liquid Penetrant Testing Process flashcards as text
Which of the following materials CANNOT be reliably inspected using liquid penetrant testing?
Answer: Porous sintered bronze bushings
Porous materials trap penetrant throughout their bulk, making it impossible to distinguish relevant indications from background bleed-out.
What is the function of the emulsifier in a post-emulsifiable penetrant system?
Answer: It makes the excess surface penetrant water-washable without affecting penetrant in discontinuities
The emulsifier combines with surface penetrant to allow water rinsing while leaving penetrant locked in discontinuities if contact time is controlled carefully.
Which environmental condition in the inspection area is MOST critical to control for fluorescent penetrant testing?
Answer: Ambient white light level (should be ≤2 fc)
Ambient white light must be ≤2 foot-candles (≤20 lux) in the inspection area so fluorescent indications are not washed out and remain clearly visible.
A rounded indication in liquid penetrant testing is MOST likely associated with which type of discontinuity?
Answer: A subsurface void or porosity cluster
Rounded indications typically correspond to porosity or globular inclusions, where the defect opening is roughly equal in all directions.
What is the maximum surface temperature typically allowed for standard penetrant materials per ASTM E1417?
Answer: 125°F (52°C)
ASTM E1417 specifies a normal operating range of 40–125°F (4–52°C) for standard penetrant materials; special high-temperature products are needed above that.
Which document establishes qualification and certification requirements for NDT personnel performing liquid penetrant testing in the aerospace industry?
Answer: NAS 410
NAS 410 (now aligned with EN 4179) defines qualification and certification requirements for NDT personnel in the aerospace industry.
When liquid penetrant testing reveals a crack-like indication at the root of a machined thread, the MOST likely cause is:
Answer: Mechanical stress concentration combined with surface fatigue or quench cracking
Thread roots are high-stress concentration zones where fatigue cracks or quench cracks commonly initiate due to combined thermal and mechanical stresses.