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ASTM D5894 correlation coefficient

I am going to do some tests with the ASTM D5894 [link is to spec at TechStreet] cyclic salt spray/QUV test. There is a correlation coefficient of 0.699 with real life defined. How does this coefficient work?

Matias Kerkhofs
- Leuven, Belgium

Sounds to me like it works through precision without accuracy :-)

There is no relationship between spray hours and real life because the corrosion mechanisms are fundamentally different, with the result that some finishes that outperform others in the test cabinet cannot actually match them in real life. So a correlation coefficient can, at most, apply only to a specific coating, not coatings in general.

Ted Mooney, P.E.
finishing.com
Brick, New Jersey

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