# Commission Delegated Regulation (EU) 2017/654 of 19 December 2016 supplementing Regulation (EU) 2016/1628 of the European Parliament and of the Council with regard to technical and general requirements relating to emission limits and type-approval for internal combustion engines for non-road mobile machinery, Appendix 1

Extent: E+W+S+N.I.

Supplementary requirements for conducting emission testing using gaseous reference fuels comprising pipeline gas with admixture of other gases
1.
Method of gas analysis and gas flow measurement
1.1.
For the purpose of this Appendix, where required the composition of the gas shall be determined by analysis of the gas using gas chromatography according to EN ISO 6974, or by an alternative technique that achieves at least a similar level of accuracy and repeatability.
1.2.
For the purpose of this Appendix, where required the measurement of gas flow shall be performed using a mass-based flowmeter.
2.
Analysis and flowrate of incoming utility gas supply
2.1.
The composition of the utility gas supply shall be analysed prior to the admixture blending system.
2.2.
The flowrate of the utility gas entering the admixture blending system shall be measured.
3.
Analysis and flowrate of admixture
3.1.
When an applicable certificate of analysis is available for an admixture (for example issued by the gas supplier) this may be used as the source of that admixture composition. In this case the on-site analysis of that admixture composition shall be permitted but shall not be required.
3.2.
Where an applicable certificate of analysis is not available for an admixture the composition of that admixture shall be analysed.
3.3.
The flowrate of each admixture entering the admixture blending system shall be measured.
4.
Analysis of blended gas
4.1.
The analysis of the composition of the gas supplied to the engine after leaving the admixture blending system shall be permitted in addition to, or as an alternative to the analysis required by points 2.1 and 3.1, but shall not be required.
5.
Calculation of Sλ and MN of the blended gas
5.1.
The results of the gas analysis according to point 2.1, point 3.1 or 3.2 and, where applicable, point 4.1, combined with the mass flowrate of gas measured according to points 2.2 and 3.3, shall be used to calculate the MN according to EN16726:2015. The same set of data shall be used to calculate Sλ according to the procedure set out in Appendix 2.
6.
Control and verification of gas blend during the test
6.1
The control and verification of the gas blend during the test shall be performed using either an open loop or closed loop control system.
6.2
Open loop blend control system
6.2.1
In this case the gas analysis, flow measurements and calculations set out in points 1, 2, 3 and 4 shall be performed prior to the emission test.
6.2.2
The proportion of utility gas and admixture(s) shall be set to ensure that the Sλ is within the permitted range for the relevant reference fuel in Table 9.1.
6.2.3
When the relative proportions have been set they shall be maintained throughout the emission test. Adjustments to individual flow rates to maintain the relative proportions shall be permitted.
6.2.4
When the emission test has been completed the analysis of gas composition, flow measurements and calculations set out in points 2, 3, 4 and 5 shall be repeated. In order for the test to be considered valid the value of Sλ shall remain within the specified range for the respective reference fuel given in Table 9.1.
6.3
Closed loop blend control system
6.3.1
In this case the analysis of gas composition, flow measurements and calculations set out in points 2, 3, 4 and 5 shall be performed at intervals during the emission test. The intervals shall be chosen taking into consideration the frequency capability of the gas chromatograph and corresponding calculation system.
6.3.2
The results from the periodic measurements and calculations shall be used to adjust the relative proportions of utility gas and admixture in order to maintain the value of Sλ within the range specified in Table 9.1 for the respective reference fuel. The frequency of adjustment shall not exceed the frequency of measurement.
6.3.3
In order for the test to be considered valid the value of Sλ shall be within the range specified in Table 9.1 for the respective reference fuel for at least 90 % of the measurement points.

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/IX/appendix/1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-IX/appendix-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.