Many people don't know the difference between NSS, AASS and CASS when doing salt spray testing.
definition:
NSS: neutral salt spray
AASS: Acetic salt mist
CASS: Copper Accelerated Acetate Salt Mist
NSS is the basis for the salt spray test, which was developed around the 1930s, and is a neutral test, meaning the test solution has a pH of 6.5-7.2.
AASS is the addition of glacial acetic acid in the pH range of 3.1 to 3.3 to NSS solution.
CASS is the method of adding copper chloride in the pH range of 3.1 to 3.3 to the AASS solution.
How to choose a test?
It is mainly based on the material and coating of the sample.
NSS is suitable for metals and their alloys, most metal coatings, anodic oxide coatings, organic coatings.
AASS can be used to test copper/nickel/chrome or nickel/chrome decorative coatings. For testing anodic coatings on aluminum
CASS can be used to test copper/nickel/chrome or nickel/chrome decorative coatings. And for testing anodic coatings on aluminum.
