CASS Test Vs Neutral Salt Spray Test

CASS Test Vs Neutral Salt Spray Test

There is often a confusion among the manufacturers whether to improvise neutral salt spray test or CASS test. Which test method would fetch better results? Making a choice would be difficult for them as customers demand test results very specifically based on procedures like ASTM B117. Well, there is a notion that neutral salt spray tester is more popular than CASS tester and gives more reliable results. In reality, both the tests give an estimation of the behaviour of the product in real working conditions. Sometimes, manufacturers are willing to perform all the test as per their clients’ demand. Presto offers multiple models of salt spray testing machine to fulfil the request of the clients. On the other hand, read on further if you are willing to understand the suitability of the test procedure for your industry.  

 
There are three types of test procedures followed
Neutral Spray
Acetic Acid Spray
Copper Accelerated Spray
 
However, the choice is made after analysing the type of coating. Acetic Acid Salt Spray and Copper-Accelerated Salt Spray (also known as AASS and CASS respectively), are mostly used for electrodeposited copper/nickel/chromium coatings, nickel/chromium coatings, and sometimes anodic coatings on aluminium.
On the other hand, the neutral salt spray is used for metal, alloys, metallic coating, anodic oxide coating and organic coatings.  
And this becomes the responsibility of the manufacturer to make the clients understand that there is no need to perform all the tests when purpose can be served by one test. To choose the best test procedure, first, you need to analyse the type of the coating on the product. However, there are many other test methods that are followed also, these tests produce a cyclic corrosive environment to relate it more to the real-time behaviour. 
 
CASS Test Procedure
Copper Accelerated Salt Spray is used to initiate the corrosion of the surface coating. The specimen is placed in the machine chamber with approx. temperature range 37°C. The duration of the test can be referred from the testing standard that is being followed. 
 
Apart from analysing the salt spray life, the CASS tester helps in identifying the regression in the production process over the years. The quality of coating should remain year after years to maintain the standards. However, due to change in techniques or workforce or machines, there is often some regression in the process. To identify the loopholes and fall in quality, this test procedure is very useful.
 
For more information related to CASS tester, call our experts.