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A salt spray test chamber can simulate a marine salt spray environment to conduct corrosion tests on test samples. The materials tested mainly include metals and some surface-plated materials, and this testing method is used to evaluate the corrosion resistance of these materials. Salt spray testing is currently divided into three types, which involve the use of three different salt solutions for corrosion testing. These three tests are the neutral salt spray test, the acidic salt spray test, and the copper-accelerated acetate salt spray test. The following mainly describes the preparation process of the copper-accelerated acetate salt spray test solution. http://www.dongguanruili.com/d/file/26c99b4ca4507b91b26e68a59cde93f2.jpg The copper salt-accelerated acetate salt spray test is similar to the other two tests; aside from the difference in testing temperature, the main distinction lies in the composition of the salt spray solution. Different salt solutions and temperatures can affect the degree of salt spray corrosion. The procedure for conducting the salt spray test using copper to accelerate the reaction of acetic acid is as follows: First, dissolve sodium chloride in distilled water or deionized water to achieve a concentration of 50±5 g/L. The sodium chloride must be white in color, and it should dissolve in water to form a colorless solution. Sodium chloride should, in principle, contain no copper or nickel, with their levels to be less than 0.1%; the total impurities, calculated on a dry salt basis, should not exceed 0.4%. If the pH of the solution used in the equipment is outside the range of 6.0 to 7.0, harmful impurities in either the salt or the water should be checked. II. Sufficient amounts of copper dichloride (CuCl2·2H2O) must be added to the salt solution, so that its concentration is 0.26±0.02 g/L (equivalent to 0.205±0.05 g/L of CuCl2·2H2O). III. Sufficient glacial acetic acid must be added to the salt solution to ensure that the pH of the salt spray solution samples collected in the salt spray test chamber remains between 3.1 and 3.3. If the pH value of the solution prepared initially is 3.1–3.3, the pH value of the sprayed solution will most likely fall within this range as well. All pH values should be measured at 25°C using a pH meter. However, precise pH test strips that can detect changes of 0.3PH and have been verified through electrical measurement can be used for regular checks. Pure glacial acetic acid or sodium hydroxide can be added for any necessary adjustments. The prepared solution must be filtered before it can be used. The solutions used in the copper-accelerated acetate salt spray test are prepared just before use, to prevent deterioration and precipitation due to long-term storage, which could affect the effectiveness of the spraying process; moreover, concentration or impurities may influence the corrosion effect. When preparing the copper-accelerated acetate solution, it is necessary to consider the total amount and concentration of the solution required for the salt spray test, in order to avoid a shortage of the salt solution.