ASTM D1298 is a widely used standard test method published by ASTM International for determining the density, relative density (specific gravity), or API gravity of crude petroleum and liquid petroleum products using a glass hydrometer.
ASTM D1298 measures:
Density (kg/m³)
Relative density (specific gravity)
API gravity (common in the oil & gas world)
A calibrated hydrometer is floated in a liquid sample at a controlled temperature. The reading is then corrected to a reference temperature (typically 15 °C or 60 °F) using standard tables.
The ASTM D1298 is used rude oil and refined fuels (diesel, gasoline, jet fuel), petroleum trading and custody transfer of quality control in refineries and labs.
The method helps classify petroleum as light or heavy. The density affects pricing, blending, transport, and processing. ASTM D1298 is a simple, low-cost method that’s trusted globally.
The sample is brought to the prescribed temperature and transferred to a cylinder at approximately the same temperature. The appropriate hydrometer is lowered into the sample and allowed to settle. After temperature equilibrium has been reached, the hydrometer scale is read, and the temperature of the sample is noted. If necessary the cylinder and its contents nnay be placed in a constant temperature bath to avoid excessive temperature variation during the test.
