IP 617: Determination of generic cetane number (G-CN) of fuels using a constant volume combustion chamber — primary reference fuels calibration (PRFC) method

Overview:

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 1 The analyser can measure ICN outside the calibrated range, but precision has not been determined.

NOTE 2 For the purpose of this standard, the expression ‘% (V/V)’ is used to represent the volume fraction.