FREE NDT Penetrant Testing Questions and Answers

Question 1

How often should one measure the strength of UV light?

Accepted Answer

All of the above

Answer

The strength of UV light is crucial for effective fluorescent penetrant inspection (FPI) and must be regularly monitored. It should be measured at the start of an inspection cycle to ensure compliance, whenever a new bulb is installed to confirm proper function, and every 8 hours during continuous use to account for bulb degradation. Regular checks ensure consistent and reliable inspection results.

Question 2

When the manufacturer initially sends the penetrant:

Accepted Answer

A sample of fresh solution should be collected and stored as a standard for future comparison

Answer

When a new batch of penetrant is received, it is essential to collect and store a sample as a reference standard. This 'control sample' allows for future comparison to monitor the performance of the in-use penetrant. By comparing the working penetrant to the fresh standard, any degradation or contamination can be detected, ensuring the penetrant maintains its required sensitivity.

Question 3

Increasing the temperature will:

Accepted Answer

Raise the speed of evaporation of penetrants

Answer

Increasing the temperature of either the penetrant or the part being inspected will accelerate the evaporation rate of the penetrant's solvent. This can cause the penetrant to dry out too quickly, potentially reducing its ability to fully enter and dwell within discontinuities. Proper temperature control is therefore crucial for consistent and effective liquid penetrant inspection.

Question 4

Most materials can be tested with LPI as long as the part's surface is

Accepted Answer

Is not extremely rough or porous

Answer

Liquid Penetrant Inspection (LPI) relies on the penetrant entering surface-breaking discontinuities. If the part's surface is extremely rough or porous, the penetrant can become trapped in the surface texture itself, leading to false indications or making it difficult to properly wash off excess penetrant. This can obscure actual defects or make interpretation unreliable, hence the need for a relatively smooth, non-porous surface.

Question 5

Which kind of penetrant is less susceptible to cleaning fluid contamination?

Accepted Answer

Type II

Answer

Type II penetrants are visible penetrants, meaning they are detected by the naked eye under white light, unlike fluorescent (Type I) penetrants. Generally, visible penetrants are considered less sensitive to minor process variations and contamination compared to fluorescent penetrants, where even slight impurities can quench fluorescence and reduce detectability. This makes Type II less susceptible to certain types of cleaning fluid contamination that might degrade fluorescent properties.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

FREE NDT Penetrant Testing Questions and Answers