DENSITY AND RELATIVE DENSITY OF VISCOUSMATERIALS BY LIPKIN PYCNOMETER: ASTM D1481
EXPLANATION
This test method is applicable to oils more viscous than 15 cSt at 20° C, and of viscous oils and melted waxes at elevated temperatures, but not at temperatures at which the sample would have a vapor pressure of 100 mm Hg (13 kPa) or above.
This test method provides a calculation for converting density to relative density (specific gravity). Densities of less viscosities at 20° or 25° C can be determined using Test Method ASTM D1217.
TEST SUMMARY
The liquid is drawn into the bicapillary pycnometer through the removable siphon arm and adjusted to volume at the temperature of test, in such a manner that there is practically no drainage in the unfilled tubing. After equilibration at the test temperature, liquid levels are read, and the pycnometer is removed from the thermostated bath, cooled to room temperature, and weighed. From the weight of the sample and the volume at the test temperature density is calculated after correcting for the effect of air buoyancy.
TEST PRECISION
This test method has a repeatability of 0.00015 and a reproducibility of 0.00035 g/mL for a 10 mL volume pycnometer. This precision may not apply if a pycnometer of volume other than 10 mL is used.
The difference of results from established values when compared to pure reference materials is not expected to be more than 0.00035 g/mL.
Specific bias has not been established for this test method.
