IEC 60068-2-11:2021 pdf download

IEC 60068-2-11:2021 pdf download.Environmental testing – Part 2-11: Tests – Test Ka: Salt mist
1 Scope
This part of IEC 60068 specifies a test method for assessing the corrosion resistance of electrotechnical products components, equipment and materials in a salt mist environment. Its objective is to verify that the comparative quality of a metallic material, with or without corrosion protection, is maintained when exposed to salt mist. This test method is useful for evaluating the quality and the uniformity of coatings applied to protect metals against corrosion. It is particularly useful for detecting discontinuities, such as pores and other defects, in certain metallic, organic, anodic oxide and conversion coatings.
4 General
WARNING – This document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For equipment and components, Test Kb (IEC 60068-2-52) is considered to provide more realistic conditions and to provide means of assessment of individual items. If, however, for particular circumstances, the relevant specification requires this test (Ka) to be applied to individual specimens for qualification purposes, then the specimens should be tested as part of the overall assembly or equipment in which they are to be used and be completed with any protection devices (cases, covers, shields, etc.), as in practice. NOTE 1 “Salt mist” is also called “salt spray”. NOTE 2 The test specimen(s) is typically not energized during the test.
5 Salt solution
5.1 Preparation of salt solution Dissolve a sufficient mass of sodium chloride in distilled or deionized water with a conductivity not higher than 20 µS/cm at 25 °C ± 2 K to produce a concentration of 50 g/l ± 5 g/l. The sodium chloride concentration of the sprayed solution collected shall be 50 g/l ± 5 g/l. The specific gravity range for a 50 g/l ± 5 g/l solution is 1,029 to 1,036 at 25 °C. The sodium chloride shall not contain a mass fraction of the heavy metals copper (Cu), nickel (Ni) and lead (Pb) in total more than 0,005 %. It shall not contain a mass fraction of sodium iodide more than 0,1 % and a mass fraction of total impurities more than 0,5 %, calculated for dry salt. NOTE Sodium chloride with anti-caking agents can act as corrosion inhibitors or accelerators. A useful sodium chloride salt grade is a grade named Ph. Eur/USP or JIS, ACS. 5.2 pH adjustment If necessary, adjust the pH of the salt solution so that the pH of the sprayed solution collected within the test chamber is 6,5 to 7,2 at 25 °C ± 2 K. Check the pH using electrometric measurement. Measurements of pH shall be done using electrodes suitable for measuring in weakly buffered sodium chloride solution in deionized water. Make any necessary corrections by adding hydrochloric acid, sodium hydroxide or sodium bicarbonate solution of analytical grade. WARNING – Hydrochloric acid (CAS no. 7647-01-0) solution is toxic, corrosive, irritating and very toxic to aquatic life. Handling of hydrochloric acid solution shall be restricted to skilled personnel or conducted under their control. Care shall be taken in the disposal of this solution. WARNING – Sodium hydroxide (CAS no. 1310-73-2) solution is toxic, corrosive and irritating. Handling of sodium hydroxide solution shall be restricted to skilled personnel or conducted under their control. Care shall be taken in the disposal of this solution. NOTE Possible changes in pH can result from loss of carbon dioxide in the solution when it is sprayed.