Which of the following factors can affect the outcomes of penetrant testing?

The correct answer is that both environmental temperature and humidity can significantly affect the outcomes of penetrant testing.

In penetrant testing, the effectiveness of the penetrant is influenced by the conditions under which the test is performed. Environmental temperature plays a crucial role because it can affect the viscosity of the penetrant, the ability of the penetrant to flow into the discontinuities, and the drying time of the developer. Higher temperatures can enhance the performance of the penetrant by allowing it to penetrate more effectively, while lower temperatures can slow down the process and lead to less reliable results.

Similarly, environmental humidity can impact the results of penetrant testing. High humidity levels can lead to condensation on the surface of the test object, which can interfere with the penetration of the dye and the subsequent readability of the indications. Adequate humidity control ensures that there is no moisture on the surface that could create false indications or prevent the penetrant from entering flaws effectively.

Considering both of these factors together highlights their interdependence in creating optimal conditions for penetrant testing, making the combined option the most appropriate answer. Material thickness, while important in other contexts, does not directly relate to the nature of the penetrant testing process itself in the ways temperature and humidity do.