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
What is the minimum dwell time typically required for liquid penetrant to enter a tight fatigue crack in steel at room temperature?
Answer: 5 minutes
A minimum of 5 minutes dwell time is typically required for penetrant to enter tight fatigue cracks in steel at room temperature.
Which surface condition would MOST adversely affect the quality of a liquid penetrant test?
Answer: A thin oil film covering the part
An oil film blocks penetrant from entering discontinuities, making pre-cleaning the most critical preparatory step.
After applying a water-washable penetrant, what is the danger of over-washing the part?
Answer: Penetrant trapped in discontinuities may be removed, causing false-negative indications
Over-washing can remove penetrant from shallow or wide-open discontinuities, causing relevant indications to be missed.
A Type II penetrant system uses which fluorescent agent characteristic?
Answer: Dye that is visible only under UV-A (black) light
Type II penetrants contain fluorescent dye that glows under UV-A (ultraviolet) light, providing high contrast against the dark inspection background.
What is the purpose of a non-aqueous wet developer in liquid penetrant testing?
Answer: To draw penetrant out of discontinuities and provide a contrasting background
Non-aqueous wet developer uses a carrier solvent that evaporates, leaving a white powder coating that draws penetrant out and creates contrast.
When inspecting a part using solvent-removable penetrant, the excess penetrant should be removed by:
Answer: Wiping with a dry cloth first, then a cloth lightly dampened with solvent
The correct technique is to wipe with a dry cloth first and then use a lightly dampened cloth to avoid flushing penetrant out of discontinuities.
In liquid penetrant testing, a 'false indication' is BEST described as:
Answer: An indication caused by improper developer application
A false indication results from faulty technique—such as improper developer application—rather than from an actual material condition.