Why is it necessary to evaluate the developer's performance regularly?

Regular evaluation of a developer's performance is crucial to ensure it does not degrade over time and continues to effectively facilitate defect visibility. The primary role of the developer in liquid penetrant testing is to draw penetrant out of any surface defects onto the surface, creating a visible indication for inspection.

As time passes, factors such as environmental conditions, storage practices, and the chemical makeup of the developer can impact its effectiveness. If the developer loses its ability to adhere to the penetrant or fails to maintain its physical and chemical properties, the visibility of defects can be significantly reduced, potentially leading to undetected flaws that could have serious implications.

Therefore, by regularly assessing the developer, inspectors can confirm its performance remains optimal, ensuring that defects are properly highlighted and that inspection results are reliable and accurate.