Liquid Penetrant Testing Level 1 (PT-1) Practice Exam

Which of the following actions is likely to result in a loss of sensitivity in the liquid penetrant examination?

1. Reprocessing a specimen which has already been examined by liquid penetrant examination method

2. Applying penetrant under a high-pressure environment

3. Storing the penetrant at room temperature

4. Using penetrant with a low viscosity

The correct answer is: Reprocessing a specimen which has already been examined by liquid penetrant examination method

Reprocessing a specimen that has already undergone liquid penetrant examination can indeed lead to a loss of sensitivity in the examination. When a part is reprocessed, residual penetrant materials may mix with subsequent applications. This can lead to the formation of a film or contamination on the surface that may obscure or mask the presence of defects such as cracks or porosity. Furthermore, the effectiveness of the penetrant can diminish if it has already been drawn out of any indications during the first examination, which would prevent subsequent inspections from revealing the same defects. Each penetrant application is designed to highlight surface defects under optimal conditions, which can be compromised by prior processing. On the other hand, applying penetrant under high-pressure environments, storing it at room temperature, or using penetrant with low viscosity are practices generally considered neutral or even beneficial to the examination process, within their established guidelines. High pressure can enhance penetrant flow into defects, room temperature storage maintains penetrant consistency up to a certain point, and low viscosity allows better penetration into smaller defects.