ASTM G85 Annex A3 Standard Practice for Modified Salt Spray (Fog) Testing
This test uses a solution of sea salt in place of the standard sodium chloride. This solution is then acidified with the use of Acetic acid until a ph of 2.8 to 3.0 is maintained.
This test is performed as a wet bottom test, i.e. about an inch or so of water should always be present at the bottom of the chamber to prevent the inside of the box from becoming dry, which would decrease the corrosion rate.
The temperature remains constant during this test. The temperature that the test is to run under is determined by the type of material being tested.
This test is particularly useful in production control of exfoliation resistant heat treatments for the 2000, 5000, and 7000 series aluminum alloys.
To obtain the complete specifications go to ASTM International.