Testing of exhaust after-treatment systems. If the engine is equipped with an exhaust after-treatment system, the emissions measured on the test cycle(s) must be representative of the emissions in the field. If this cannot be achieved with one single test cycle (e.g. for particulate filters with periodic regeneration), several test cycles must be conducted and the test results averaged and/or weighted. The exact procedure must be agreed by the engine manufacturer and the Technical Service based upon good engineering judgement. __________" Annex 4 – Appendix 1, amend to read: "Annex 4 - Appendix 1 ESC AND ELR TEST CYCLES
