This International Standard specifies a method for the determination, using an oscillating U-tube density meter, of the density of crude petroleum and related products within the range 600 kg/m3 to 1 100 kg/m3 which can be handled as single-phase liquids at the test temperature and pressure. This International Standard is applicable to liquids of any vapour pressure as long as suitable precautions are taken to ensure that they remain in single phase. Loss of light components will lead to changes in density during both the sample handling and the density determination. This method is not intended for use with in-line density meters.