Downloaded from https://www.everyspec.com MlL-STD-81OC 3.1.4.1 Measurement of sodium chloride content. The solution, maintained at the specified temperature, can be measured in a graduate of approximately 2.5 centimeters inside diameter. A small laboratory t~e hydrometer will be required for measurement within this volume. 3.1.4.2 Measurement of PH. The pH shall be measured as specified in 2.4.1. 3.1.4.3 Time ef measurements. The measurement of both sodium chloride content,and pH shal1 be made at the followingspecified times: a. For salt fog chambers in continuous use, the measurements shall be made following each test. b.
For salt fog chambers that are used infrequently, a 24-hour test run shall be accomplished followed by the measurements. The test item shall not be exposed to this test rim. 3.1.S Preparationof test item. The test “item’shall be given a minimum of handling, particularly on the significant surfaces, and shall be prepared for test immediatelybefore exposure. Unless otherwise specified, uncoated ‘metallicor metallic coated devices shall b6 thoroughly cleaned of oil, dirt, and grease as necessary until the surface is free from water break.
~The cleaning methods shal1 not include the use of corrosive solvents nor solvents which deposit either corrosive or protective films, nor the use of abrasives other than a paste of pure magnesium oxide, Test items having an organic coating shall not be solvent cleaned. Those portions of test items which come in contact with the support and, unless otherwise ‘specifiedin the case of coated devices or samples, cut edges and surfaces hot required to be coated, shall be protected with a suitable coating of wax or similar substance impervious to moisture. 3.1.6 Performance of test.
The test item shallbe placed in the test chamber in accordance with General Requirements, 3.2.2, and exposed to the salt fog for a period of 48 hours or as specified in the equipment specifi- cation. At the end of the exposure period, unless otherwise specified, the test item shall be operated and the results compared with.the data obtained in accordance with General Requirements, 3.2.1. The test item shall be in- spected for corrosion in accordance with General Requirements 3.2.4. If necessary to aid in examination, a gentle wash in running water not warmer than 38°C (1OO”F) may be used.
The test item shall then be stored in an ambient atmosphere for 48 hours or as specified in the equipment specifi- cation for drying. At the end of the .dryifigperiod, when specified, the test item shal1 be again operated and the results compared with the data obtained in accordance with General Requirements,‘3.2.1. The test item shall then be inspected in accordance with ,GeneralRequirements, 3.2.4. 509.1-7 METHOD 509.1