1.1 Chemically pure sodium chloride is dissolved into distilled or deionized water, to produce a solution at a concentration of 50±5g/L.
1.2 An acidometer is used to measure pH value of the solution, or the precision pH paper calibrated using an acidometer may be used for daily testing. pH value of solution may be adjusted with chemically pure hydrochloric acid or sodium hydroxide. The pH value of salt spray solution collected within the test chamber will be set between 6.5 and 7.2.
1.3 The solution must be filtered prior to use, in order to avoid blocking the nozzle.
2 Test Equipment
2.1 The materials used to manufacture test equipment must be resistant to salt spray corrosion and have no influence on the test results.
2.2 The chamber shall not be less than 0.2 m3 in volume and had better not less than 0.4m3; the liquid drops accumulated on the top shall not fall onto the test specimen. Shape and dimension of the chamber shall be in such that salt spray solution collected within the chamber meets the requirements of 5.2.
2.3 It shall be able to maintain the temperature at each position in the chamber meet the requirements of 5.1. Thermometer and automatic temperature control elements shall be kept at a distance not less than 100mm to the inner wall of the chamber, and it shall be possible to read the results outside the chamber.
2.4 The spray device consists of the following parts.
