Liquid Penetrant Testing Level 2 (PT-2) Practice Exam

While performing a fluorescent water washable penetrant test, which of the following steps should be performed under black light?

1. Penetrant application

2. Excess penetrant removal

3. Emulsification

4. Developer application

The correct answer is: Excess penetrant removal

In a fluorescent water washable penetrant test, performing the excess penetrant removal step under black light is essential to ensure effective interpretation of results. When excess penetrant is removed while the part is illuminated by black light, it allows the inspector to see any penetrant that remains in the discontinuities more clearly, as the fluorescent penetrant will glow brightly against the dark background. This enhances the visibility of any indications present, making it easier for the inspector to determine if defects are present. By removing excess penetrant in this way, the inspector can ensure that the proper amount of penetrant is left to highlight any potential defects while minimizing contamination from excess penetrant that could obscure the results. It also sets a proper contrast for the subsequent inspection steps, ensuring higher accuracy in evaluating the inspection results. In fluid penetrant testing, the other steps, such as penetrant application, emulsification, and developer application, do not typically require the use of black light for effective execution, as their main purpose is to allow the penetrant to penetrate the defects, emulsify for washability, and then draw the penetrant out of the defects respectively.