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

Which statement is NOT true regarding oil removal prior to penetrant testing?

1. It is necessary to remove a film of oil from a part

2. It is not necessary to remove oil because the penetrant is basically oil

3. Oil can interfere with the penetrant’s effectiveness

4. Removal of oil increases sensitivity

The correct answer is: It is not necessary to remove oil because the penetrant is basically oil

The statement that it is not necessary to remove oil because the penetrant is basically oil is not true. In liquid penetrant testing, the presence of oil can interfere with the effectiveness of the penetrant. Although penetrants may contain oil-based materials, any existing oil film on the surface of the part can create a barrier that prevents the penetrant from properly entering surface defects. It's crucial to thoroughly clean the surface and remove any oil, grease, or other contaminants prior to testing to ensure that the penetrant can effectively seep into any cracks or imperfections. This step is vital for achieving accurate results during the inspection process. Additionally, cleaning surfaces enhances the sensitivity of the test, as it allows the penetrant to fully function without obstruction, making it possible to detect even the smallest defects. Thus, removing oil not only aids in the penetrant's effectiveness but also enhances the overall sensitivity of the testing process.