For how long is a penetrant allowed to soak in cracks?
(a) 5 to 15 minutes
(b) 10 to 30 minutes
(c) 15 to 35 minutes
(d) 20 to 40 minutes
I have been asked this question in my homework.
Question is taken from Dye Penetrant Test in division Non Destructive Techniques of Casting-Forming-Welding II