Author Archives: metlchek

Known Defect Test Piece part 2

Known Defect Test Piece Part Deux In the March 2016 Penetrant Professor we discussed known defect standards for penetrant inspection and introduced a new star burst type panel, the Hoffman Panel. We commented that this panel at that time had not been officially approved to the Pratt & Whitney TAM...

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Low/High Temperature and Penetrants

This subject was discussed in our 2nd anniversary issue of the Penetrant Professor in 1995. Funny how time flies but the questions remain the same. Every penetrant manufacturer is asked about what temperature their penetrant should be used at. In the case of Met-L-Chek penetrants, the label on the aerosol...

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Engine Crankshaft Inspection, circa 2005

THE ENGINE CONUNDRUM Last month, we related the story of the person who wanted to inspect a crankshaft for cracks, but who didn’t want to disassemble the engine. The question that was posed was whether the penetrant could be applied to the outside of the engine to locate a flaw...

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The Penetrant Process – Iowa State University

Iowa State University has done some work regarding penetrant testing. Individual topics on their work have been presented before, but this time it was all put together. We want to list some of the highlights of their work and to refer you to the places where you can look at...

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The Evolution of Penetrant Specifications

A Few More Thoughts On The Evolution of Penetrant Specifications The past two issues of the PENETRANT PROFESSOR have concentrated on the historical path of the relevant qualifying documents and the journey to develop a method of measuring absolute sensitivity. While these have been extremely important in the creation of...

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Penetrant Application & Sensitivity

Penetrant Application & Sensitivity How is the best way to apply penetrant, and does the method of application have any bearing on the sensitivity of the process? This is a question that arises from time to time. It is not a question about the sensitivity of the penetrant, which is...

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Emulsifier Concentration

One might assume that all inspectors understand what the concentration of their hydrophilic emulsifier should be. For dip tanks, most specifications require that the concentration be maintained between 17% and 20%, and for spray application that the concentration be less than 5 %. These are verified by using a refractometer...

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So, What Is This (M) and What Does It Mean??

Strangely enough we get this question frequently, concerning our post emulsified fluorescent penetrants. These are listed as follows: Level 1 sensitivity – FP-94 Level 2 sensitivity – FP-93A(M) Level 3 sensitivity – FP-95A(M) Level 4 sensitivity – FP-97A(M) This nomenclature resulted from a massive change in the qualification requirements in...

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