MIL-STD-810G Method 518.2 Acidic Atmosphere Test

The purpose of this test is to evaluate ammunition's acid resistance and protective coatings against corrosive environments.

Substances that are likely to be stored or operated in an industrial area or an area with an acidic atmosphere, such as the exhaust pipe of any fuel combustion system, are the subject of this test.

It is not a substitute for the chlorinated fog method and is not suitable for evaluating the effect of acidic sulfur, which easily oxidizes and forms sulfur dioxide in the test environment.

Effects

Representative case effects from exposure to an acidic atmosphere

• A. Chemical effect on surface finish and non-metallic ammunition.
• B. Metal corrosion.
• C. Dents in cement and fiber materials.

Determination of test level and conditions

3-1. Exposure temperature and exposure time (intensity and exposure time - Cycle)

• 3 times 2 hours spray test + 22 hours storage
• 4 times 2 hours spray test + 7 days storage

3-2. Chemical composition of the test atmosphere and concentration of the test solution.

• Ionized water + sulfuric acid solution + nitric acid solution

Test procedure

A. Set the reservoir temperature (35°C, minimum 2 hours)

B. Exposure of elements to harsh conditions

• 3 times 2 hours spray test + 22 hours storage
• 4 times 2 hours spray test + 7 days storage

C. Standard Atmospheric

D. Visual inspection