Euro 6: emission measurements (chassis dynamometer, PEMS), autonomy...
The Euro 6 standard includes several revisions: Euro 6b, Euro 6c or Euro 6.2, Euro 6d-TEMP including Euro 6d-TEMP-EVAP-ISC, Euro 6d or Euro 6d Full which widen the envelope of required tests and lower the limits of pollution emissions (limits of NOx (nitrogen oxides), CO (carbon monoxide), fine particles (PM/PN) and unburned hydrocarbons (HC)).
From January 1, 2021, the Euro 6.d Full standard is strengthening the limit on pollutant emission limits that must not be exceeded. Carbon monoxide (CO), hydrocarbons (HC), or nitrogen oxide (NOx) are particularly targeted.All types of engines are concerned: diesel and petrol cars, as well as those with a hybrid or LPG engine.
Our Osny site is accredited to EN 17025 for exhaust emissions testing on a chassis dynamometer and for exhaust emissions testing on an open road (RDE) for light vehicles (CO2 / CO / NOx / Particulate Matter / Consumption measurements)
Euro 6 : The main requirements
Since 2014, the Euro 6 standard has been applied and has also evolved with, among other things, the increase in testing in real driving conditions. A vehicle must now pass a series of tests concerning:
- exhaust emissions (gazeous and particulate) in laboratory (WLTC) and real driving conditions (RDE), emissions in low ambient temperature, idling emissions, exhaust gas opacity, the right operation and the regeneration of subsequent treatment systems
- evaporative emissions (EVAP tests) and crankcase emissions;
- on-board diagnostics systems and performance in use of pollution control devices - Alert in case of malfunction of the pollution control systems (OBD);
- sustainability of pollution control devices;
- In-Service Conformity (ISC Tests)
- the energy consumption indicator (OBFCM and FCM)
- …
The WLTC is a dyno-based cycle, similar to the NEDC cycle. However, the WLTC aims to correct the weaknesses of the NEDC. It includes stronger acceleration and higher average speed. Nevertheless, being a laboratory test, there is always a gap between the consumption evaluated during the test and the one reached in reality.
Real driving Emissions (RDE) measurements are used to correlate pollutant emissions measured in the laboratory for the certification cycle to the real world driving of a vehicle on the road.
All greenhouse gases and pollutant emissions are measured during an RDE test but only NOx emissions are discriminating. For example, for Euro 6d full, NOx emissions must not exceed 1.5 times the allowable emissions for a vehicle approved under this standard.
RDE tests are performed on open roads near our Osny center with our PEMS.
These include the different steps of the WLTC. They must start with an urban section, followed by a rural section and a highway section. The real-world driving tests are conducted on roads with altitudes below 700 meters and temperatures between 0°C and 30°C.
These low temperature emissions tests are mainly for gasoline engines. For diesel engines, the low temperature tests must demonstrate that the NOx treatment devices are operational at the latest 400s after a cold start (ambient temperature of -7°C).
Emissions tests measure carbon monoxide emissions as well as hydrocarbon emissions by carrying out the urban cycle portion of the NEDC.
These tests are carried out in climatic test chambers equipped with chassis dynamometers.
Idle emissions measurements are only relevant for gasoline engines. They concern carbon monoxide (CO) emissions with a CO content not exceeding 0.3%.
Crankcase emission measurements are made only on vehicles with spark-ignition engines. To measure the efficiency of the suction system, the vehicle is set on a chassis dynamometer and subjected to 3 different configurations: engine idle, vehicle running at 50 km/h and vehicle loaded at 50 km/h.
The durability test is intended to assess the degradation of the emission control systems after the vehicle has been driven for a significant number of kilometres.
The ageing process can be carried out on an engine test bench with, first, a WLTP test carried out on a complete vehicle and another WLTP test carried out after the ageing process. At the end of this test, the pollutant emissions are measured according to the WLTP cycle. The values measured must not exceed the standards that the vehicle meets.
The test can also be carried out on a complete vehicle with 160,000 km driven on a chassis dynamometer (or on the road).
For an internal combustion engine, the power and torque characteristics are evaluated on an engine test bench, including the essential parts for its operation and if possible, without the gearbox. The engine power characteriztion is done by taking these values over all possible speeds (from idle to maximum speed).
For electric motors, the power measurement is carried out in two phases.
The initial phase consists of measuring the power of the engine from 0 to maximum rotation speed. In the second phase, the engine power is evaluated over a period of 30 minutes in a speed range that corresponds to the speeds where the engine delivers 90% of the maximum power measured in the first test.
This test is for vehicles already in circulation that must also have remained in compliance with emissions regulations. These tests are required for all approvals since January 1, 2019 and for all new registrations since September 1, 2019.
The manufacturer must guarantee the vehicle's compliance with the certification data for a period of at least 5 years or 100,000 km, whichever comes first. The In service Conformity concerns the emission tests of pollutant gases, measured in chassis dyno and in real driving conditions, and the evaporation tests.