Liquid Penetrant Testing Level 2 (PT-2) Practice Exam

Which type of developer does not provide a contrasting background against which to view penetrant indications?

1. Dry

2. Non-aqueous wet

3. Water soluble

4. Water suspendable

The correct answer is: Dry

The choice of a dry developer in Liquid Penetrant Testing is notable because it does not create a contrasting background for viewing penetrant indications. Dry developers are typically powdery substances that can absorb penetrant but do not enhance the visibility of indications in the way that wet developers can. Wet developers, whether they are non-aqueous or water-soluble, create a contrast against the penetrant indications by forming a film or layer that highlights the defects more clearly. In contrast, water suspendable developers can also provide a more visible background, serving to enhance the detection of indications when penetrant is applied. The lack of contrast with dry developers means that while they can be useful for removing excess penetrant, they do not facilitate the identification of indications as effectively as other options. Therefore, when it comes to identifying and viewing penetrant indications, a dry developer lacks the needed contrasting background.