The test standard summaries are for general guidance only. Though believed to be accurate at the time of writing, this may change over time. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level.
Note: the terms salt spray, salt mist & salt fog are all in wide spread use within corrosion test standards. In this context they can be considered to be equivalent and interchangeable terms.
IEC 60068-2-52 – Methods 7-8
Test specimens are placed in an enclosed chamber (a separate salt mist chamber and controlled humidity chamber are generally used) and exposed to a changing climate that starts with 2 hours exposure to a continuous indirect spray of neutral (pH 6.5 to 7.2) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +15 to +35°C. Depending upon method number, this is followed either by exposure to a high humidity climate of 40°, C93%RH; or air drying at 60 °C, under 30 % RH and then Wetting at 50°C.
The duration of high humidity and number of cycle repeats is variable depending on the test method (1-8).
Test method 7
One cycle is 8 h. One cycle shall consist of spraying the specimen with salt solution at 35 °C for 2 h, followed by the dry condition at 60 °C, under 30 % RH for 4 h and then the humid condition at 50 °C, over 95 % RH for 2 h.
The transition times (time allowed to reach the temperature and relative humidity specified for a condition after changing to that condition) for temperature and humidity shall be specified between the following choices and reported: – salt mist to dry condition: within 30 min or between 30 min and 60 min; – dry condition to humid condition: within 15 min or between 15 min and 30 min; – humid condition to salt mist: within 30 min. Those transition times shall be included in the next condition period of the pair, for example the salt mist to dry condition transition time is included in the period of the dry condition. Spraying the specimen with a salt solution begins instantaneously once the salt mist is started.
The recommended number of cycles are 3 (1 day), 6 (2 days), 12 (4 days), 30 (10 days), 45 (15 days), 60 (20 days), 90 (30 days), 150 (50 days) and 180 (60 days).
Test method 8
One cycle is 8 h, as specified in test method 7 using acidified salt solution instead of neutral salt solution.
The recommended number of cycles is the same as in test method 7