General
Originally this test method was developed for the determination of density of ASTM Knock Test Reference Fuels with an accuracy of 0.00003 g/mL. Although it is no longer used extensively for that purpose, the method is still useful whenever accurate densities of pure hydrocarbons or petroleum fractions with boiling points between 90 and 100°C are required.
Precision
This test method has a repeatability of 0.00002 and a reproducibilityof 0.00003.
Specific bias has not been determined.
Test
The liquid sample is introduced into a pycnometer equilibrated to the desired temperature, and weighed. Weight of water required to fill the pycnometer at the same teniperature is also measured. Both weights are corrected for the buoyancy of air before calculating density and relative density.