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The Euro 7 emission regulations currently under consideration by the EU will adopt on-road emissions test as the main Type Approval procedure, and it has been proposed that the number of gas components to be measured will be increased. Therefore, the Portable Emissions Measurement System (PEMS) used for on- road emissions testing must be able to simultaneously measure more components with higher precision while maintaining the same compact and lightweight structure as in the existing PEMS. The authors have applied a relatively new technique, quantum cascade laser infrared spectroscopy (QCL-IR), to an on-board multi-component gas analyzer. Comparison with laboratory tests on a gasoline passenger car on a dynamometer showed that the newly developed QCL- IR PEMS correlated well with conventional PEMS and stationary conventional analyzers.

Recently, after-treatment techniques for diesel engine emission have made remarkable progress with the development of suitable De-NOx catalysts. The urea-injection SCR system is one of the candidates for a high efficiency De-NOx method for diesel engine emissions. This system reduces NOx through a reaction with ammonia (NH3) that is generated from injected urea. In this system, it is very important to control the amount and timing of the urea injection so as to minimize the NH3 gas slip. Therefore, NH3 gas measurement is becoming important during the development of NOx after-treatment systems even though NH3 is not a target component of the current emission regulations. In this paper, a new NH3 gas analyzer utilizing a chemi-luminescence detection (CLD) method has been developed. The new NH3 analyzer consists of dual detectors (DCLDs) and a furnace for a NH3 oxidization catalyst. Real-time concentration of NH3 can be calculated from the difference of NOx readings of two detectors.

The use of alternative fuels, especially oxygenated fuels in automobile engines, has been increasing owing to the stringent global fuel economy and emission regulations. As a result, it is concerned that the emissions of alcohols and aldehydes have increased significantly. Aldehydes, formaldehyde (HCHO) in particular, are non-criteria pollutants that are acutely toxic and/or carcinogenic. Several reports have associated HCHO with potential lung and airway cancers. Therefore, emission regulations for these compounds have already been implemented in several areas worldwide. The conventional measurement (impinger, etc.) methods for HCHO possess advantages and disadvantages. HCHO can be measured with high sensitivity if measured in a batch. However, in real-time measurements, low concentration measurements are challenging.

The European Union has announced the next term emission regulations for light-duty vehicles which include particle number (PN) emission standards. The protocol for PN counting for the regulation is described in UNECE Regulation No.83. The PN counting system required for this regulation should consist of a Volatile Particle Remover (VPR) and a Condensation Particle Counter (CPC). The regulation also requires calibration of the VPR's Particle Concentration Reduction Factor (PCRF) periodically. Since the PCRF is directly used in the calculation of PN emission, an improper calibration of the factor can cause a significant error of PN emission result. This paper investigates propriety to use NaCl particles generated by atomizing method in the PCRF calibration as reference particles. As a result, it is shown that the NaCl particles can be used in PCRF calibration because of the sufficient stability when appropriate thermal treatment is applied.

The measurement protocol of solid particle number with the lower detection limit (D50) at 10 nm (SPN10) is planned to be implemented in European emission regulations by means of laboratory-grade measurement systems. Furthermore, SPN10 measurement as the real driving emissions (RDE) regulations is under development by defining appropriate technical specifications for the portable emissions measurement system (PEMS). It is under discussion to implement SPN10 limits as one of additional pollutants to the new European emissions regulations, so-called “Euro 7”. As the Consortium for ultra LOw Vehicle Emissions (CLOVE) has proposed, RDE testing by means of PEMS will be the primary means of emissions determination for certification purposes. Measurement equivalency between laboratory-grade emissions measurement systems and PEMS is still important due to the necessity of validation in laboratories before on-road testing by comparing determined emissions by both.