What is the effect of humidity on Liquid Penetrant Testing results?

High humidity can significantly impact the effectiveness of Liquid Penetrant Testing. When humidity levels are elevated, it can adversely affect the adhesion of the penetrant to the surface being examined. This poor adhesion occurs because moisture on the surface can interfere with the penetrant's ability to properly cling to it, making it more challenging for the penetrant to enter any surface discontinuities. Consequently, this can yield less accurate or less reliable test results as the penetrant may not adequately infiltrate the defects present.

Furthermore, high humidity might also affect the developer's performance. The presence of moisture can hinder the developer's ability to attract and release the penetrant from the defects, leading to insufficient contrast and difficulty in detecting flaws. Therefore, maintaining appropriate humidity levels is crucial for ensuring optimal conditions during Liquid Penetrant Testing, making option C the accurate choice in this context.