This European Standard specifies a test method for the quantitative determination of the indicated cetane number (ICN) of middle distillate fuels and blending components, intended for use in compression ignition engines. The test method utilizes a constant volume combustion chamber with direct fuel injection into heated compressed air. Calibration of the apparatus using blends of primary reference materials over a scale of 0 to 100 enables fuel ignition delays, measured from the resulting pressure increase, to be used to determine and report ICN results.This European Standard is applicable to middle distillate fuels of both petroleum and non-petroleum origin, hydrocarbon oils, oil-sands based fuels, blending components, fatty acid methyl esters (FAME), blends of fuel containing biodiesel material, diesel fuel oils containing cetane number improver additives, low-sulfur diesel fuel oils, aviation turbine fuels and polyoxymethylene dimethyl ether (OME). However, users applying this standard especially to unconventional distillate fuels are warned that the relationship between cetane number and combustion behaviour in real engines is not yet fully understood.This European Standard covers the calibrated range of 35 ICN to 85 ICN.NOTE 1The analyser can measure ICN outside the calibrated range, but precision has not been determined.NOTE 2For the purpose of this standard, the expression "% (V/V)" is used to represent the volume fraction.WARNING - The use of this standard can involve hazardous materials, operations and equipment. This Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of users of this standard to take appropriate measures to ensure the safety and health of personnel prior to application of the standard, and fulfil statutory and regulatory requirements for this purpose.