In this test cycles of 1hr
dry-off and 1hr fog are utilized. The electrolyte is a solution of
sodium chloride and ammonium sulfate and is more dilute than the traditional salt spray fog test. The fog portion of
this test is conducted at room temperature, the dry-off portion, however, is
performed at an elevated temperature. Also the spray atomizing air is not
saturated with water for this test.
The electrolyte solution
consists of 0.05% sodium chloride and 0.35% ammonium sulfate by mass. The sodium chloride and water are subject to the same purity requirements as
for the other test in this specification. The ammonium sulfate shall not
contain more than 0.3% total impurities. To obtain complete specifications go to ASTM International.
The temperature throughout
the exposure zone during the dry-off phase shall reach and remain
constant at 35°C plus or minus 6 1.5°C (95°F plus or minus 3°F) within 3⁄4-h
of switching from the fog period to the dry period.