ASTM D1481 Standard Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Lipkin Bicapillary Pycnometer
12. Precision and Bias
12.1 The precision of the method as obtained by statistical examination of interlaboratory test results is as follows:
12.1.1 Repeatability - The difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the following value only in one case in twenty:
12.1.2 Reproducibility - The difference between two single and independent results, obtained by different operators working in different laboratories on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the following value only in one case in twenty:
NOTE 5 - If pycnometers of other than 10 mL in volume are used, this precision statement may not apply.
12.2 Bias - The difference of results from the established value when compared to pure reference materials is not expected to be more than 0.000 35 g/mL. Specific bias has not been established by cooperative testing.
13. Keywords
13.1 density; gravity; pycnometer; relative density; specific gravity