EN 16906:2017

European foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents and materials
6 Apparatus
7 Sampling
8 Standard operating and test conditions
9 Calibration, verification and quality control
10 Procedure
11 Calculation
12 Expression of results
13 Precision
Annex A (informative) - Evaluation example of
        the cetane number using a calibration graph
Annex B (normative) - Auxiliary digital equipment
Bibliography

This European Standard specifies a test method for the determination of cetane numbers ("CN") in diesel fuel in the range from CN 45 to CN 63, using a standard single cylinder, four-stroke cycle, indirect injection engine. The cetane number provides a measure of the ignition characteristics of diesel fuels in compression ignition engines. The cetane number is determined at constant speed in a compression ignition test engine equipped with a swirl chamber.This European Standard is applicable to distillate as well as paraffinic diesel fuels intended for use in diesel engines, including those containing and fatty-acid methyl esters (FAME), ignition-improvers or other additives. The cetane number scale comprises a range from zero to 100, but typical testing is currently performed in the range from about 40 CN to about 75 CN.This engine test procedure may be used for other fuels such as synthetics and vegetable oils. However, samples with fuel properties that interfere with the gravity-based pre-supply pressure to the fuel pump e.g. due to high viscosity can only be used to a limited extent. Precision data for such fuels are not available at this stage. Precision data for paraffinic diesel fuels are currently under development.NOTE 1For the purpose of this European Standard the expressions "%(m/m)" and "%(V/V)" are used to represent the mass faction and volume fraction respectively of a material.NOTE 2The test method is also suitable for determining cetane numbers outside the range of the scope, however, the precision statement only applies for fuels in the specified range.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 the user 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.