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

What is the primary purpose for using a developer on a test specimen?

1. To color the surface

2. To absorb penetrant from discontinuities and provide a contrasting background

3. To clean the surface prior to testing

4. To enhance the visibility of surface defects

The correct answer is: To absorb penetrant from discontinuities and provide a contrasting background

The primary purpose of using a developer on a test specimen is to absorb penetrant that may be trapped in discontinuities, such as cracks or voids, and to provide a contrasting background. The developer plays a crucial role in the liquid penetrant testing process by drawing the penetrant out of these small defects that might not be visible on the surface. This action allows for better visualization of the indications or defects during inspection. When the developer is applied, it creates a chalky white or colored background that contrasts with the color of the penetrant. This contrast enhances the ability to see any defects present on the specimen, improving the overall effectiveness of the inspection. The developer's ability to create this visual separation is essential for inspectors to accurately identify and assess flaws within materials.