Density is one of the most frequently tested properties in the hydrocarbon trade. It is used to convert volumes into masses, and therefore to calculate invoiced quantities, but also to check whether a fuel meets its specification.
How the method works
ASTM D1298 describes how to measure the density, relative density or API gravity of crude oil and liquid petroleum products using a glass hydrometer. The sample is placed in a cylinder and brought to a stable temperature, then the hydrometer is lowered until it reaches equilibrium. The reading is then corrected to the reference temperature of 15 °C.
Why temperature matters
Hydrocarbons expand with heat. A measurement taken without temperature control can skew quantity calculations by several tenths of a percent, which represents large volumes across an entire cargo. That is why our laboratory uses a temperature-controlled bath that keeps the cylinders at a constant temperature throughout the measurement.
What it means for you
A density measured according to the standard, with verified equipment and controlled temperature, allows you to secure your quantity calculations, detect possible contamination or blending and rely on a defensible result in the event of a commercial dispute.
Our laboratory performs this test on crude oil, fuels and lubricants, and issues a certificate of analysis.
