The heavy duty emissions requirements specified by EC Regulation No. 595/2009 and implemented by EU Regulation No. 582/2011 require engines to be tested on an engine dynamometer,following a specific drive cycle, during which the emissions of carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx), ammonia (NH3) and both the mass and number of particulate matter (PM) are measured. This engine dynamometer test is supplemented by complete vehicle emissions tests using portable emissions measuring systems (PEMS). PEMS testing is carried out at the time of type approval to assess the engine's "off cycle" emissions and is also carried out on in-service vehicles to verify conformity with the emissions requirements during the full "useful life" of the engine. However, during PEMS testing, only the emissions of carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx) are measured.
The reason why the emissions of particulate matter is not currently measured during PEMS testing is that, when PEMS testing was originally introduced, the PEMS equipment and the test procedures for the measurement of particulate matter emissions were still under development. However, this development process has now reached a stage where the PEMS equipment and test procedures for the measurement of the mass of particulate matter emissions have been demonstrated as reliable and repeatable enough for them to be introduced into the type approval legislation. Therefore, at a meeting of the Technical Committee- Motor Vehicles (TCMV) held on 10th September, 2015, the European Commission submitted a proposal to amend EU Regulation No. 582/2011 to introduce particulate matter mass measurements into the PEMS testing requirements. (Note: The development of PEMS equipment and test procedures for the measurement of the number of particulate matter emissions is still ongoing and, according to the European Commission, is unlikely to be completed and validated for another 3 to 4 years.)
In addition to the introduction of particulate matter mass measurements into the PEMS testing requirements, the proposal submitted by the European Commission also covers the following:
- The introduction of refinements and clarifications to the PEMS testing specifications and selection criteria.
- The introduction of a durability test specification for the testing of replacement pollution control devices to the Euro VI emissions requirements.
- Alignment of the requirements on anti-tampering with those specified in UN ECE Regulation No. 49.
With regard to introduction dates, the European Commission are proposing that compliance with the PEMS requirements on particulate mass measurement become mandatory for all new vehicles from 31st December 2016.