1. Scope*
1.1 This test method covers the determination of the density, relative density, and API
Gravity of petroleum distillates and viscous oils that can be handled in a normal
fashion as liquids at the temperature of test, utilizing either manual or automated
sample injection equipment. Its application is restricted to liquids with total vapor
pressures (see Test Method D5191) typically below 100 kPa and viscosities (see Test
Method D445 or D7042) typically below about 15 000 mm2/s at the temperature of test. The total vapor pressure limitation however can be
extended to >100 kPa provided that it is first ascertained that no bubbles form in
the U-tube, which can affect the density determination. Some examples of products
that may be tested by this procedure include: gasoline and gasoline-oxygenate blends,
diesel, jet, basestocks, waxes, and lubricating oils.
1.1.1 Waxes and highly viscous samples were not included in the 1999 interlaboratory study
(ILS) sample set that was used to determine the current precision statements of the
method, since all samples evaluated at the time were analyzed at a test temperature
of 15 °C. Wax and highly viscous samples require a temperature cell operated at elevated
temperatures necessary to ensure a liquid test specimen is introduced for analysis.
Consult instrument manufacturer instructions for appropriate guidance and precautions
when attempting to analyze wax or highly viscous samples. Refer to the Precision and
Bias section of the method and Note 9 for more detailed information about the 1999
ILS that was conducted.