Which factor can hinder the testing process in LPT?

Low temperatures can significantly hinder the liquid penetrant testing (LPT) process due to their impact on the performance of the penetrant materials. In lower temperature conditions, the viscosity of the penetrant increases, making it less effective at penetrating surface openings such as cracks and voids in the material being tested. Additionally, low temperatures can affect the activation and drying times of both the penetrant and the developer, potentially leading to incomplete or inaccurate indications of defects. An effective LPT process relies on optimal environmental conditions to ensure that the penetrant can adequately penetrate and be subsequently revealed, making temperature control essential for successful testing.

High humidity can also affect testing, but in a different manner, while excessive lighting generally enhances visibility during interpretation rather than hindering it. Proper technique is crucial for achieving reliable results and does not act as a hindrance.