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Different particulate mass (PM) portable emission measurement systems (PEMS) were evaluated in the lab with three heavy-duty diesel engines which cover a wide range of particle emission levels. For the two engines without Diesel Particulate Filters (DPF) the proportional partial flow dilution systems SPC-472, OBS-TRPM, and micro-PSS measured 15% lower PM than the full dilution tunnel (CVS). The micro soot sensor (MSS), which measures soot in real time, measured 35% lower. For the DPF-equipped engine, where the emissions were in the order of 2 mg/kWh, the systems had differences from the CVS higher than 50%. For on-board testing a real-time sensor is necessary to convert the gravimetric (filter)-based PM to second-by-second mass emissions. The detection limit of the sensor, the particle property it measures (e.g., number, surface area or mass, volatiles or non-volatiles) and its calibration affect the estimated real-time mass emissions.

The regulation of particle number (PN) has been introduced in the Euro 5/6 light-duty vehicle legislation, as a result of the light duty inter-laboratory exercise of the Particle Measurement Program (PMP). The heavy-duty inter-laboratory exercise investigates whether the same or a similar procedure can be applied to the heavy-duty regulation. In the heavy-duty exercise two "golden" PN systems sample simultaneously; the first from the full dilution tunnel and the second from the partial flow system. One of the targets of the exercise is to compare the PN results from the two systems. In this study we follow a different approach: We use a PMP compliant system at different positions (full flow, partial flow and tailpipe) and we compare its emissions with a "reference" system always sampling from the full flow dilution tunnel.

Fuel consumption is already one of the parameters taken into account for the final ranking of some competitions organized by the Federation International de l'Automobile (FIA). Pollutant emissions, such as CO, HC and NOx, could also be taken into consideration in the near future. In occasion of a competition organized by the FIA in the framework of the “Alternative Energies Cup” championship, several vehicles were equipped for demonstration and scientific purpose with portable emission measurement systems (PEMS) in order to measure the gaseous emissions during the competition. The competition took place at the Autodromo Nazionale of Monza on the same track used for the Formula 1 Grand Prix as well. For this competition the track was divided into three sections simulating respectively the typical speeds and driving patterns on urban roads, on extra-urban roads and on motorways.

The heavy duty Particle Measurement Programme (PMP) inter-laboratory exercise consists of three parts: 1) the exploratory work to refine the measurement protocol, 2) the validation exercise where each lab will measure the emissions of a “golden” engine with two “golden” particle number systems simultaneously sampling from full and partial flow dilution systems, and 3) the round-robin where the emissions of a “reference” engine will be determined with a lab’s own particle number instrumentation. This paper presents the results of the exploratory work and describes the final protocol for testing in the validation exercise (and round robin) along with the necessary facility modifications required for compliance with the protocol. Key aspects of the protocol (e.g. filter material, flow rates at the full and partial flow systems, the pre-conditioning etc.) are explained and justified.

Measurement of particle number was introduced in the Euro 5/6 light duty vehicle emissions regulation. Although particle number measurement systems have to be calibrated by the manufacturers, labs have to validate the proper operation of their systems within one year of the emissions test. The systems must achieve a >99% reduction of an aerosol containing 30 nm tetracontane (CH3(CH2)38CH3) particles (C40) with an inlet concentration >104 #/cm3. They must also include an initial heated dilution stage with dilution of at least 10 which outputs a diluted sample at a temperature of 150°C–400°C. The system as a whole must achieve a particle number concentration reduction factor for particles of 30 nm and 50 nm electrical mobility diameters, that is no more than 30% and 20% respectively higher, and no more than 5% lower than that for particles of 100 nm.

This work was conducted in order to study the effect of Combustion Chamber Deposits (CCD) on engine-out hydrocarbon emissions. A bench engine test based on the CEC-F-20 test procedure was used to accumulate CCD. The experiments were performed on a 2.0 L, four-cylinder engine with multipoint fuel injection. All measurements were carried out under steady state operating conditions at full load on the engine. The measurement of exhaust hydrocarbons was accomplished with a fast-response FID analyser, with the sample probe being installed close to the exhaust valves in the exhaust port of cylinder #1 and #4, respectively. Interpretation of the measurements was based on the typical hydrocarbon curve measured by the fast FID during the exhaust phase of the combustion cycle. In order to emphasize the CCD effect, three pure component fuels of differing volatilities were used. Test results indicated that CCD gave an increase of total HC amount.

The development of the On-Board Diagnostic Systems (OBD) requires the determination of the critical level of the poisoning of the exhaust aftertreatment components. In order to have an accurate analysis, one way is to separate the effect of the poisoning of the two components: oxygen sensor and three way catalyst [ 1 ]. Our experimentation has been concentrated on poisoning of lambda sensor. An apparatus fed with model gases was realized to evaluate the poisoning of oxygen sensors coming from a fleet test of 6 taxis after a mileage of 100000 km. Our apparatus has been able to differentiate the poisoning level of the sensors by measuring their “switchability”. To confirm these measurements the lambda sensor switchability has been verified with a bench test using the Mercedes- Benz M111E engine. Exposing the aged lambda sensor to the engine exhaust gas, its response was coherent with its behavior on the apparatus fed with model gases.