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Particulate matter (PM) emission from vehicles is one of the biggest issues in terms of environmental protection and influence to human body. Thus, a variety of measurement technologies have been develop so far. Currently, a gravimetric method is most commonly used in the automotive industry, partially because it is specified in the regulations. This method uses a combination of a dilution tunnel and a filter that collects the PM from the diluted sample gas with subsequent weighting by a micro balance. However, since this technique is a batch measurement, it is impossible to determine at what point of the emissions test the Soot, SOF (Soluble Organic Fraction), and the total PM are emitted. Thus the demand for real-time PM measurement under transient test conditions has increased.

An approach for raw exhaust gas sampling, different from the conventional diluted exhaust gas sampling method, has been adopted for a solid particle counting system developed in the previous study. The system has been applied for evaluating solid particle emission from a DI diesel engine with DPF. In addition the filtration efficiency of the DPF has been tested from the real time concentrations, measured at upstream and downstream of the DPF. High accuracy and stability of measurement of the system against high exhaust gas pressure condition have been confirmed. The system response satisfies the requirement of ISO 8178-11. Excellent correlation of direct sampling and diluted gas sampling has been achieved with this system. It is found that the filtration efficiency changes during the engine test cycle and is strongly affected by the pre-conditioning of DPF.

A sulfur analyzer utilizing an ultraviolet fluorescent (UVF) detector has been developed to measure sulfur components in vehicle emissions. Generally, it is considered that an UVF detector cannot be used to measure sulfur components in vehicle emission due to a significant interference from NO in sample gases. In this study, an O3 injection technique has been developed to eliminate NO interference. Using this technique, the interference from NO has been reduced to less than 0.01 ppm with 3000 ppm NO. These result show a capability of utilizing UVF with this O3 injection technique to measure sulfur components in vehicle emissions including emissions with high concentrations of NO. An oxidation catalyst has also been evaluated to measure total reduced sulfur, TRS.

The environmental effects of particulate matter (PM) emissions from vehicles are an increasing concern to those concerned with air quality. A variety of technologies have been developed to measure exhaust particulates. The automotive industry generally uses the gravimetric method to quantify particulate emissions. This method uses a combination of a dilution tunnel and filter to collect PM from the diluted sample gas. The collected PM is later weighed on a microbalance. Because this technique is a batch measurement, it is not possible to determine at what point of an emissions test drive cycle the soot, soluble organic fraction (SOF) and total PM are emitted. A more accurate characterization of PM emissions will require real-time PM measurement under transient test conditions.