13. Interpretation of Results
13.1 Report Group 1 samples (Table 1) as passing the test only when the oil layer shows no change in color and when the acid layer is not darker than the specified color standard. A cloudiness or haze in the oil layer should not be interpreted as a change in color.
13.2 When testing samples of Groups 2 or 3, disregard the color of the oil layer and report the sample as passing the test when the acid layer is not darker than the specified color standard.
14. Precision and Bias
14.1 Precision data have not been established for all types of samples on which this test method is used. Limited cooperative tests were conducted in 1961, principally to establish equality with the previously used shaking procedure. Precision estimates taken from these data are as follows:
15. Keywords
15.1 acid wash color; aromatic hydrocarbons