Rust-preventing characteristics of inhibited mineral oil in the presence of water
12. Interpretation of Results
12.1 Perform all inspections at the end of the test to determine the condition of test rods without magnification under normal light. For the purpose of this test, normal light is considered to be illumination of about 60 footcandles (650 lx). Within the meaning of this test method, a rusted test rod is one on which any rust spot or rust streak is visible by the above inspection procedure.
12.2 For the purpose of this test method, rust is an area of corrosion of the test surface that is identified by color and is confirmed by the presence of pits or roughness if the surface is wiped with a lintless cloth or tissue paper. Neither surface discoloration nor specks, which can easily be removed with a lintless or tissue paper cloth with no evidence of pitting or roughness, shall be considered to be rust.
12.3 In order to report an oil as passing or failing, conduct the test in duplicate. Report an oil as passing the test if both test rods are rust-free at the end of the test period. Report an oil as failing the test if both test rods are rusted at the end of the test period (see Note 16). If one test rod is rusted while the other is free of rust, test two additional test rods (see Note 9). If either of these latter test rods shows rusting, report the oil as not passing the test. If neither of these latter test rods shows rusting, report the oil as passing the test.
NOTE 16 - An indication of the degree of rusting occurring in this test may be desired. For uniformity in such cases, use of the following classifications of rusting severity is recommended:
Light Rusting - Rusting confined to not more than six spots, each of which is 1 mm or less in diameter.
Moderate Rusting - Rusting in excess of the above but confined to less than 5 % of the surface of the test rod.
Severe Rusting - Rusting covering more than 5 % of the surface of the test rod.
12.4 A reference oil with a Pass in Procedure A and a Fail in Procedure B can be prepared as follows: Add 0.0150 mass % of an additive concentrate to a white mineral oil. The additive concentrate consists of 60 mass % of dodecenyl succinic acid and 40 mass % of normal paraffin oil, ISO VG 22 (see Classification D 2422).
