Principles
DPI is based upon capillary action, where low surface tension fluid penetrates into clean and dry surface-breaking discontinuities. Penetrant may be applied to the test component by dipping, spraying, or brushing. After adequate penetration time has been allowed, the excess penetrant is removed, a developer is applied. The developer helps to draw penetrant out of the flaw where an invisible indication becomes visible to the inspector. Inspection is performed under ultraviolet or white light, depending upon the type of dye used - fluorescent or nonfluorescent (visible).
Read more about this topic: Dye Penetrant Inspection
Famous quotes containing the word principles:
“Ah, I fancy it is just the same with most of what you call your “emancipation.” You have read yourself into a number of new ideas and opinions. You have got a sort of smattering of recent discoveries in various fields—discoveries that seem to overthrow certain principles which have hitherto been held impregnable and unassailable. But all this has only been a matter of intellect, Miss West—superficial acquisition. It has not passed into your blood.”
—Henrik Ibsen (1828–1906)
“Now there cannot be first principles for men, unless the Divinity has revealed them; all the rest—beginning, middle, and end—is nothing but dreams and smoke.”
—Michel de Montaigne (1533–1592)
“It is the genius of our Constitution that under its shelter of enduring institutions and rooted principles there is ample room for the rich fertility of American political invention.”
—Lyndon Baines Johnson (1908–1973)