The authors would like to thank Sensors Inc. for providing a PEMS for conducting an inter-laboratory exercise.

<ol>
	<li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Regulation No 83 on uniform provisions concerning the approval of vehicles with regard to the emission of pollutants according to engine fuel requirements, Addendum 82: Regulation No 83, Revision 4. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+No.+715/2007+of+the+European+Parliament+and+of+the+Council+of+20+June+2007on+type-approval+of+motor+vehicles+with+respect+to+emissions+from+light+passenger+and+commercial+vehicles+(Euro+5+and+Euro+6)+and+on+access+to+vehicle+repair+and+maintenance+information,+European+Commission+(EC).">Regulation No. 715/2007 of the European Parliament and of the Council of 20 June 2007on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, European Commission (EC).</a> Official J. European Union. L 171, 1-16 (2007).</li><li>Tietge, U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> From laboratory to road: a 2015 update of official and "real-world" fuel consumption and CO2 values for passenger cars in Europe. ICCT white paper. , (2015).</li><li>Weiss, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On-road+emissions+of+light-duty+vehicles+in+Europe.">On-road emissions of light-duty vehicles in Europe.</a> Environ. Sci. Technol. 45, 8575-8581 (2011).</li><li>. Determination of PEMS measurement allowances for gaseous emissions regulated under the heavy-duty diesel engine in-use testing program. Revised Final report Available from: <a target="_blank" href="https://www.regulations.gov/document?D=EPA-HQ-OAR-2004-0072-0085">https://www.regulations.gov/document?D=EPA-HQ-OAR-2004-0072-0085</a> (2008)</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-use+emissions+testing+with+Portable+Emissions+Measurement+Systems+(PEMS)+in+the+current+and+future+European+vehicle+emissions+legislation:+Overview,+underlying+principles+and+expected+benefits.">In-use emissions testing with Portable Emissions Measurement Systems (PEMS) in the current and future European vehicle emissions legislation: Overview, underlying principles and expected benefits.</a> SAE Int. J. Commer. Veh. 7 (1), 199-215 (2014).</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+vehicles+real-driving+emissions+performance:+a+challenge+for+the+emissions+control+legislation.">Evaluating vehicles real-driving emissions performance: a challenge for the emissions control legislation.</a> VDI Research Reports. , (2015).</li><li>Hausberger, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiences+with+current+RDE+legislation.">Experiences with current RDE legislation.</a> , (2015).</li><li>Demuynck, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Euro+6+Vehicles'+RDE-PEMS+Data+Analysis+with+EMROAD+and+CLEAR.">Euro 6 Vehicles' RDE-PEMS Data Analysis with EMROAD and CLEAR.</a> , (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+2016/427.+Amending+Regulation+(EC)+No+692/2008+as+regards+emissions+from+light+passenger+and+commercial+vehicles+(Euro+6)).+Annex+IIIA+of+the+Commission+Regulation+(EC)+No.+692/2008+(2016).+Verifying+Real+Driving+Emissions.">Commission Regulation 2016/427. Amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6)). Annex IIIA of the Commission Regulation (EC) No. 692/2008 (2016). Verifying Real Driving Emissions.</a> Official J. European Union. L 82, 1-97 (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+2016/646.+Amending+Regulation+(EC)+No+692/2008+as+regards+emissions+from+light+passenger+and+commercial+vehicles+(Euro+6).+Annex+IIIA+of+the+Commission+Regulation+(EC)+No.+692/2008+(2016).+Verifying+Real+Driving+Emissions.">Commission Regulation 2016/646. Amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6). Annex IIIA of the Commission Regulation (EC) No. 692/2008 (2016). Verifying Real Driving Emissions.</a> Official J. European Union. L 109, 1-22 (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+(EC)+No.+692/2008+of+18+July+2008+implementing+and+amending+Regulation+(EC)+No+715/2007+of+the+European+Parliament+and+of+the+Council+on+type-approval+of+motor+vehicles+with+respect+to+emissions+from+light+passenger+and+commercial+vehicles+(Euro+5+and+Euro+6)+and+on+access+to+vehicle+repair+and+maintenance+information,+European+Commission+(EC).">Commission Regulation (EC) No. 692/2008 of 18 July 2008 implementing and amending Regulation (EC) No 715/2007 of the European Parliament and of the Council on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, European Commission (EC).</a> Official J. European Union. L 199, 1-135 (2008).</li><li>. On-road determination of average Dutch driving behaviour for vehicle emissions. TNO Report 2016 R 10188 Available from: <a target="_blank" href="https://www.researchgate.net/publication/303809697_On-road_determination_of_average_Dutch_driving_behaviour_for_vehicle_emissions">https://www.researchgate.net/publication/303809697_On-road_determination_of_average_Dutch_driving_behaviour_for_vehicle_emissions</a> (2016)</li><li>Bosteels, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real+Driving+Emissions+and+Test+Cycle+Data+from+4+Modern+European+Vehicles.">Real Driving Emissions and Test Cycle Data from 4 Modern European Vehicles.</a> , (2014).</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Euro+6+Real-Driving+Emissions+(RDE)+procedure+for+light-duty+vehicles:+Effectiveness+and+practical+aspects.">The Euro 6 Real-Driving Emissions (RDE) procedure for light-duty vehicles: Effectiveness and practical aspects.</a> , (2016).</li><li>Giechaskiel, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vehicle+emission+factors+of+solid+nanoparticles+in+the+laboratory+and+on+the+road+using+Portable+Emission+Measurement+Systems+(PEMS).">Vehicle emission factors of solid nanoparticles in the laboratory and on the road using Portable Emission Measurement Systems (PEMS).</a> Front. Environ. Sci. 3 (82), (2015).</li><li>. Preliminary uncertainty assessment. Presentation given to the European Commission, RDE Task Force on Uncertainty Evaluation Available from: <a target="_blank" href="https://circabc.europa.eu/sd/a/a4c8455f-de18-4f3a-9571-9410827c4f87/2015_10_01_Error_analysis_JRC.pdf">https://circabc.europa.eu/sd/a/a4c8455f-de18-4f3a-9571-9410827c4f87/2015_10_01_Error_analysis_JRC.pdf</a> (2015)</li></ol>

The views expressed here are those of the authors and may not be regarded as the official position of the European Commission.
Mention of trade names or commercial products does not constitute endorsement or recommendation by the authors or the European Commission.

In this paper, the RDE procedure was described. Several points deserve special attention and will be discussed in more detail here.
For type approval purposes, it is obligatory to determine the exhaust gas flow using equipment such as an EFM functioning without any connection to the ECU of the vehicle. Regarding vehicle preparation, the connection between the EFM and the tailpipe is important. The materials should be temperature- and exhaust gas composition-resistant. Although this is not so critical for NOx, it will be significant for particle number sampling, where desorption of deposited material can lead to artificially high emissions. In addition, points that can accumulate condensates should be avoided. The condensates formed during accelerations can enter into the measurement systems and damage or block them. The sampling points of the analyzers are connected downstream of the EFM in order to ensure that the whole flow passes through the EFM. In case this is not possible and they are connected upstream of the EFM, a correction for the extracted flow has to be made. The analyzers should be connected downstream of the EFM, without any modifications to the length of the sampling lines. If this is not possible, the residence time in the extra tubing has to be taken into account in the software in order to ensure correct emission calculations. The analyzers can be installed inside or outside of the vehicle, as long as safety requirements are met. Moreover, the calibration of the analyzers requires attention. It has to be done within the expected range of emissions of the vehicle. Otherwise, the requirement of 90% coverage of 99% of the measurements of the valid parts of the emissions test might not be fulfilled.
The trip verification and the calculation of the emissions are typically conducted by the PEMS software. For normal driving, all conditions can be easily met17. For example, based on our measurements, a normally driven trip is well within the dynamic boundary limits (Figure 4). However, aggressive driving can be within the pass zone, especially during the urban or motorway portions. On the other hand, data in Dutch cities show that normal driving can also exceed these limits18. In the future, experience over time, tests conducted closer to the boundary conditions, and evaluation methods that show differences of &#62;50% will assess the applicability of the procedure11,19.
A source of uncertainty originates from the determination of road loads for the measurement of CO2 emissions with the WLTC; these measurements are used to evaluate the normality of driving conditions with the RDE data evaluation. Ideally, the chosen road loads resemble those of the unloaded vehicle tested with the PEMS on the road. The flexibilities granted in by the WLTP (e.g., to determine the road load based on conservative generic parameters or the vehicle with the highest test mass within a family) may cause substantial deviations in the CO2 emissions determined by the WLTC and measured later on the road. In consequence, the methods may yield a biased evaluation of the actual driving severity. The WLTP provisions for setting the road load may potentially need to be specified for RDE purposes.
It should be noted that, in comparison to the European heavy-duty in service conformity regulation, there are some differences (e.g., drift correction is allowed, OBD connection is necessary in order to calculate emissions in g/kWhr) due to the different type approval procedure for the heavy-duty vehicles (engines)6. The differences are out of the scope of this paper. With the US in-use-compliance regulation, there are more differences in the evaluation method.
Worldwide, RDE marks the first regulatory on-road test for light-duty vehicles. The RDE provisions defined in Regulation 2016/427 mark the first relevant instance for the type approval of light-duty vehicles in Europe, where RDE complements the standard vehicle testing under controlled conditions in the laboratory. The RDE test procedure allows for testing, and thus controlling, vehicle pollutant emissions under a wide range of operating conditions and in a more robust and comprehensive manner than the currently-applied laboratory testing with a predefined driving cycle.
Nevertheless, RDE is also subject to limitations. First, modal emission measurements on the road over long time periods entails the risk of analyzer drift (e.g., due to variability in ambient temperature). On-road emission measurements are thus subject to larger uncertainty margins (estimated at a maximum of 20-30% at the applicable emissions limit for NOx)21 than emission measurements in the laboratory, even if PEMS analyzers fulfill similar requirements regarding accuracy and precision as laboratory analyzers. Second, the handling of PEMS equipment requires training; conducting emission tests on the road is not yet plug-and-play, and it requires an expert. As on-road testing with PEMS is still rather novel, training that allows auto makers and technical services to acquire and share best practices is needed. The present article is an attempt to disseminate knowledge on the handling of PEMS and the testing of vehicle emissions on the road. Larger-scale experience with the RDE provisions, as can be obtained by inter-laboratory exercises or through benchmarking against existing international legislation, is still missing. As RDE constitutes the first on-road test procedure for light-duty vehicles worldwide, the European Commission foresees an annual review of conformity factors and a more comprehensive review of the entire RDE procedure in the midterm.
There are two major areas for future application. First, RDE may be adopted by other countries. China, India, Japan, and South Korea are interested in adopting RDE, or elements thereof, for regulatory purposes. As such, the procedure described here may become the blueprint for regulatory on-road emissions testing of light-duty vehicles around the world. Second, RDE presents a good practice guide for any independent emission test performed by research institutions and technical services. The provisions help ensure accurate and robust on-road emission measurements.

Vehicles are tested in controlled laboratory conditions to determine their official emission values and fuel consumption (e.g., United Nations Economic Commission for Europe (UNECE) Regulation 83)1. For light-duty vehicles, Regulation 715/20072 defines the Euro 5 and 6 emission limits, to which vehicles in categories M1, M2 (passenger cars), N1, and N2 (vehicles for the carriage of goods) must comply. Compliance is verified by the so-called &#34;Type I&#34; test that measures tailpipe emissions after a cold start during a standardized test in the laboratory1. Although laboratory testing ensures reproducibility and comparability of results, it covers only a small range of the ambient, driving, and engine operating conditions that typically occur on the road. As a matter of fact, official laboratory test results reflect less and less the actual fuel consumption experienced by drivers on the road3. In addition, on-road vehicle emissions, specifically the NOX emissions of diesel cars, are also higher than the type-approval values4-5. Regulation 715/20072 contains provisions to ensure that the emission limits are respected under normal vehicle operation and use. Various new regulatory components are in the pipeline in order to reduce observed discrepancies, such as the World Harmonized Light-Duty Procedure (WLTP), mainly for CO2 and fuel consumption, and the Real-Driving Emissions (RDE) test procedure, mainly for pollutants.
Admittedly, the most important component of the new regulatory package for conventional pollutants is that compliance with the emission limits needs to be demonstrated over real-world vehicle operation following the RDE procedure. The new procedure will complement the measurement of emissions on the chassis dynamometers, so that a thorough control of regulated pollutants is achieved both in the laboratory and on the road. The RDE is based upon on-road emissions testing with the Portable Emissions Measurement Systems (PEMS). PEMS are not new, especially for heavy-duty vehicle testing. The United States Environmental Protection Agency (US-EPA) has added to the laboratory certification tests additional emissions requirements with the Not-To-Exceed (NTE) concept based on vehicle testing with PEMS. In Europe, PEMS-based In-Service Conformity (ISC) provisions for the EURO VI standards are applicable for EURO V engines6,7. PEMS measure emissions in the engine exhaust with a measurement performance (e.g., linearity, accuracy) that is comparable to that of laboratory-grade equipment8. The newest generation of PEMS weigh 30 kg, are compact, and can be easily installed in small passenger cars, thus having a minor impact on the vehicle.
To cope with the real-world variability of testing conditions, specific testing and data evaluation procedures must be implemented. Testing may occur under a wide range of altitude, temperature, and driving conditions. However, requirements concerning (i) trip composition (e.g., roughly equal shares of urban, rural, and motorway driving) and (ii) driving dynamics (e.g., the permissible range of accelerations) aim to ensure that vehicles are tested in a fair, representative, and reliable manner. Still, due to a number of factors (e.g., traffic, driver, and wind), any on-road test remains, to some extent, random and non-reproducible. Thus, the main challenge was the development of a data evaluation method that assesses ex post the normality of test conditions to enable a reliable assessment of vehicle emissions. To this end, two methods were adopted within the RDE: the moving averaging windows (MAW) and the power binning method. The MAW method divides the test into sub-sections (windows) and uses the distance-specific average carbon dioxide (CO2) emissions of each window to assess the normality of operating conditions. The power binning method categorizes the instantaneous on-road emissions into power bins based on the corresponding power at the wheels. The normality of the resulting power distribution is established through a comparison with a standardized wheel-power frequency distribution. Both methods include criteria to ensure that a realized test covers the range of driving dynamicity permitted by the RDE test procedure9-10. The two methods typically give results within 10%; however, differences on the order of 50% have been reported11,12. An in-depth assessment of the two data evaluation methods is still missing. The European Commission acknowledges this shortcoming in Recital 14 of the RDE Regulation13,14 and foresees a review of these two methods in the near future with the objective of retaining them or developing a unified method for the evaluation of gaseous pollutants and particle number emissions.
Until now, two RDE packages have been adopted by the Technical Committee on Motor Vehicles (TCMV) of the EU Member States and became law after their publication in the Official Journal of the European Union13-15. The first RDE package covered the boundary conditions, the actual test procedure, the PEMS specifications, and the data evaluation methods (MAW and/or power binning), but not emission limits (the package was voted on by the TCMV on the 18th of May 2015). The second RDE package added the not-to-exceed (NTE) emission limits applicable to RDE testing. In addition, complementary boundary conditions were introduced to check the excess or absence of driving dynamics. The emissions of each valid individual RDE test must be below the respective NTE emission limit, referred to in the regulation as conformity factors. Currently, only NOx emissions are covered. Binding conformity factors will be introduced in two steps: a factor 2.1 of the Euro 6 NOx limit (80 mg/km) will be applicable from 2017-2019 for new type approvals and all new car registrations. The conformity factor will subsequently be lowered to 1.5 in 2020-2021. The final Euro 6 conformity factor of 1.5 provides an allowance of 0.5 (i.e., 50%) for the additional measurement uncertainty of PEMS compared to laboratory equipment and the test-to-test emissions variability within the possible ranges of testing conditions (e.g., temperature, dynamics, and altitude). Regarding CO, although binding conformity factors are currently not discussed, on-road CO emissions have to be measured and recorded to obtain type approval. The second package was voted on by the TCMV on the 28th of October 2015.
The kick-off meeting of two additional packages was held on the 25th of January 2016. The third RDE package will address particle number PEMS testing, cold start emissions, and the testing of hybrid vehicles. Measuring particle number emissions on-board vehicles is challenging, as no verified technique has yet been established. New concepts and approaches were developed in the period between 2013 and 2014, including electrical detection of aerosol in real-time combined with constant flow sampling16. This package is to be voted on in the second half of 2016. The fourth RDE package will deal with the definition of requirements for in-service conformity and market surveillance testing. Completion of this package is foreseen by early 2017. The RDE Regulations 2016/42713 and 2016/64614 are currently integrated together with the Worldwide Harmonized Light-duty Vehicles Test Procedure (WLTP) into a larger EU type approval regulation that will supplement Regulation 715/20072.
The objective of this paper is to present the experimental procedures required by the newly-adopted RDE regulation. The RDE test procedure defines the boundaries of permissible test conditions, the protocol for testing vehicles, the requirements for instruments, and the evaluation methods to be applied for analyzing vehicle operation and the related pollutant emissions (Table 1). The procedure can be summarized in six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. If any of the requirements in any of these six steps is not met, the test is considered failed. For a more detailed description of the RDE test procedure, the reader can refer to the regulation itself13-14.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Annex IIIA of EC Regulation 692/2008</td>
		</tr>
		<tr>
			<td>1. Introduction, definitions and abbreviations</td>
		</tr>
		<tr>
			<td>2. General requirements on conformity factors</td>
		</tr>
		<tr>
			<td>3. RDE test to be performed</td>
		</tr>
		<tr>
			<td>4. General requirements</td>
		</tr>
		<tr>
			<td>5. Boundary conditions</td>
		</tr>
		<tr>
			<td>6. Trip requirements</td>
		</tr>
		<tr>
			<td>7. Operational requirements</td>
		</tr>
		<tr>
			<td>8. Lubricating oil, fuel and reagent</td>
		</tr>
		<tr>
			<td>9. Emissions and trip evaluation</td>
		</tr>
		<tr>
			<td>Appendices</td>
		</tr>
		<tr>
			<td>Appendix 1:Test procedure for vehicle emissions testing with a PEMS</td>
		</tr>
		<tr>
			<td>Appendix 2: Specifications and calibration of PEMS components and signals</td>
		</tr>
		<tr>
			<td>Appendix 3: Validation of PEMS and non-traceable exhaust mass flow rate</td>
		</tr>
		<tr>
			<td>Appendix 4: Determination of emissions</td>
		</tr>
		<tr>
			<td>Appendix 5: Verification of trip dynamic conditions with method 1 (Moving Averaging Window)</td>
		</tr>
		<tr>
			<td>Appendix 6: Verification of trip dynamic conditions with method 2 (Power Binning)</td>
		</tr>
		<tr>
			<td>Appendix 7: Selection of vehicles for PEMS testing at initial type approval</td>
		</tr>
		<tr>
			<td>Appendix 7a: Verification of overall trip dynamics</td>
		</tr>
		<tr>
			<td>Appendix 7b: Procedure to determine the cumulative positive elevation gain of a trip</td>
		</tr>
		<tr>
			<td>Appendix 8: Data exchange and reporting requirements</td>
		</tr>
		<tr>
			<td>Appendix 9: Manufacturer&#39;s certificate of compliance</td>
		</tr>
	</tbody>
</table>
Table 1: Structure of the RDE regulation. The regulation is considered to be ANNEX IIIA of Commission Regulation 692/200810. All parts and appendices are described in Commission Regulation 2016/427 (the first package)8. Appendices 7a and 7b, as well as the conformity factors, are described in Commission Regulation 2016/646 (the second package)9.

<table><tbody><tr><td>PEMS analyzer</td><td>Sensors Inc.</td><td>SEMTECH ECOSTAR</td><td></td></tr><tr><td>PEMS analyzer</td><td>AVL</td><td>MOVE</td><td>&lt;strong&gt;Figure 2&lt;/strong&gt;</td></tr><tr><td>PEMS analyzer</td><td>Horiba</td><td>OBS</td><td>&lt;strong&gt;Figure 2&lt;/strong&gt;</td></tr><tr><td>PEMS analyzer</td><td>MAHA</td><td>PEMS-GAS</td><td>&lt;strong&gt;Figure 2&lt;/strong&gt;</td></tr><tr><td>Exhaust Flow meter</td><td>Sensors Inc.</td><td>SEMTECH EFM-HS</td><td>EFM-HS specifications of &lt;strong&gt;Table 4&lt;/strong&gt;</td></tr><tr><td>GPS</td><td>Garmin</td><td>Drive 50</td><td></td></tr><tr><td>Weather station</td><td>Waisala</td><td>AWS310</td><td></td></tr><tr><td>Zero gas</td><td>Air Liquide</td><td>AL089</td><td>Alphagaz 1 (N&lt;sub&gt;2&lt;/sub&gt;)</td></tr><tr><td>Span gas</td><td>Air Liquide</td><td>SM190022710IT</td><td>1,800 ppm NO in N&lt;sub&gt;2&lt;/sub&gt;</td></tr><tr><td>Span gas</td><td>Air Liquide</td><td>SM190022710IT</td><td>13% CO&lt;sub&gt;2&lt;/sub&gt; in N&lt;sub&gt;2&lt;/sub&gt;</td></tr><tr><td>Batteries</td><td>Discover</td><td>EV12A-A</td><td></td></tr><tr><td colspan="4">Mention of trade names or commercial products does not constitute endorsement or recommendation by the authors or the European Commission</td></tr></tbody></table>

implementation of portable emissions measurement systems (pems) for the real-driving emissions (rde) regulation in europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.

An example of the function of the RDE requirements will be given.
Select and prepare the vehicle and design and conduct the trip: This was not a type approval test but an application of the RDE procedures. Thus, the selected vehicle, a Euro 5B light-duty turbocharged gasoline direct injection vehicle (1.2-L engine displacement), was already available in the JRC laboratory. An RDE-compliant trip was selected (Figure 3). After installation and preparation of the PEMS, the trip was conducted.
<img alt="Figure 3" src="/files/ftp_upload/54753/54753fig3.jpg" /> 
Figure 3: Trip design. A trip that includes urban (&#8804;60 km/hr), rural, and motorway (&#62;90 km/hr) parts in equal shares is shown. The design is based on the speed limits of the chosen roads. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54753/54753fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Verify the trip: The trip was verified by checking (i) the boundary and operation conditions and (ii) the normality of driving. The boundary and operation conditions and the trip requirements were fulfilled (Table 5). The ambient temperature and the maximum altitude were both within the moderate limits of 0-30 &#176;C and &#8804;700 m, respectively. The trip consisted of urban driving followed by rural and motorway driving. It lasted 96 min and covered a distance of at least 16 km for each of the U/R/M portions. The distance shares were within 29-44% for the urban part and 23-43% for the rural and motorway parts. The trip showed stop periods, defined as periods with a vehicle speed of less than 1 km/hr, in the prescribed range of 6-30% of the urban operation duration. As far as the vehicle speed profiles are concerned, the test showed a motorway operation that properly covered (i) the range between 90 and 110 km/hr and (ii) speeds above 100 km/hr for at least 5 min. The maximum vehicle speed was well below the threshold of 145 km/hr, while the average speed of the urban driving part of the trip, including stops, was within the permissible range of 15-40 km/hr. The cumulative positive elevation gain over the entire trip was below the limit of 1,200 m per 100 km. The altitude difference between the start and end points was &#60;100 m. The relative positive acceleration and the 95th percentiles of the speed multiplied by the positive acceleration were within the limits (see Figure 4). Experimental data with more aggressive driving using the same car, as well as other tests reported in the literature, are shown for comparison17,18.
<img alt="Figure 4" src="/files/ftp_upload/54753/54753fig4.jpg" /> 
Figure 4: Indices to check the excess or absence of driving dynamics. (a) 95th percentile of the product of instantaneous speed and positive acceleration during urban, rural, and motorway driving. (b) Relative positive acceleration during urban, rural, and motorway driving. The open squares are the experimental results. The open triangles are results with aggressive driving in the same car. The asterisks are aggressive trips in German cities. The continuous line shows the permitted limits. The pass or fail areas are also shown. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54753/54753fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Conditions</td>
			<td>Units</td>
			<td>Limits</td>
			<td>Trip</td>
			<td>Urban</td>
			<td>Rural</td>
			<td>Motorway</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Speed</td>
			<td>[km/hr]</td>
			<td></td>
			<td></td>
			<td>&#8804;60</td>
			<td>60&#60;v &#8804;90</td>
			<td>v&#62;90</td>
			<td></td>
		</tr>
		<tr>
			<td>Payload</td>
			<td>[%]</td>
			<td>90</td>
			<td>75</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Ambient temperature</td>
			<td>[&#176;C]</td>
			<td>-7&#8230;+35</td>
			<td>19</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok (moderate)</td>
		</tr>
		<tr>
			<td>Max. altitude</td>
			<td>[m]</td>
			<td>&#8804;1,300</td>
			<td>302</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok (moderate)</td>
		</tr>
		<tr>
			<td>Start/End altitude difference</td>
			<td>[m]</td>
			<td>&#60;100</td>
			<td>40</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Cumulative positive elevation gain</td>
			<td>[m/100 km]</td>
			<td>&#60;1,200</td>
			<td>636</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Relative Positive Acceleration</td>
			<td>[m/sec2]</td>
			<td>Figure 4</td>
			<td></td>
			<td>0.215</td>
			<td>0.134</td>
			<td>0.100</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>speed x positive acceleration</td>
			<td>[m2/sec3]</td>
			<td>Figure 4</td>
			<td></td>
			<td>15.5</td>
			<td>22.7</td>
			<td>21.4</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Trip duration</td>
			<td>[sec]</td>
			<td>90-120</td>
			<td>96</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Distance covered</td>
			<td>[km]</td>
			<td>&#62;16</td>
			<td></td>
			<td>29</td>
			<td>27</td>
			<td>23</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Share</td>
			<td>[%]</td>
			<td>23(29)-43</td>
			<td></td>
			<td>36.7</td>
			<td>34.2</td>
			<td>29.1</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Stop time (of Urban duration)</td>
			<td>[%]</td>
			<td>&#160;6-30</td>
			<td></td>
			<td>28.8</td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>v&#62;100 km/hr</td>
			<td>[min]</td>
			<td>&#8805;5</td>
			<td></td>
			<td></td>
			<td></td>
			<td>9.7</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>v&#62;145 km/hr (of Motorway time)</td>
			<td>[%]</td>
			<td>&#60;3</td>
			<td></td>
			<td></td>
			<td></td>
			<td>0</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Average speed (Urban part)</td>
			<td>[km/hr]</td>
			<td>15-40</td>
			<td></td>
			<td>28</td>
			<td>75</td>
			<td>114</td>
			<td>ok</td>
		</tr>
	</tbody>
</table>
Table 5: Summary of trip evaluation. The boundary conditions; the test requirements; and the results obtained before and/or during the trip for the urban, rural, and motorway portions, respectively, are listed.
The normality of driving was conducted with the MAW evaluation method, excluding cold start and idling and weighing the NOx emissions with CO2 emission deviations greater than 25% of the type approval cycle according to the MAW method (see Appendix 5)8. The free EMROAD software was used.
Calculate the RDE emissions: The analysis of the results was also conducted with the EMROAD software. The results can be seen in Figure 5. The urban NOx emissions were at the same level as or lower than the respective WLTC phases emissions (0.02 g/km). The rural and motorway emissions were &#62;0.05 g/km higher than the respective WLTC phases. On average, the on-road emissions were 0.056 g/km, which is lower than the NTE limit (for this case, 0.06 mg/km x 2.1 conformity factor). Thus, this specific vehicle would pass the RDE test (even though the RDE procedure is not applicable to Euro 5 vehicles). More examples can be found elsewhere17-18.
<img alt="Figure 5" src="/files/ftp_upload/54753/54753fig5.jpg" /> 
Figure 5: MAW NOx emissions of the road trip as a function of the MAW speed. The blue squares show the average NOx emissions of each moving averaging window as a function of the respective window-average vehicle speed. Solid diamonds depict the mean on-road NOx emissions of all windows representing urban, rural, and motorway driving. White circles depict the laboratory NOx emissions over the four phases of the WLTP. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54753/54753fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe at JoVE.com

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

The European Commission has developed a Real-Driving Emissions (RDE) test procedure to verify pollutant emissions during real-world vehicle operation using the Portable Emissions Measurement Systems (PEMS). This paper presents the experimental procedures required by the newly-adopted RDE test.

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. ...

implementation-portable-emissions-measurement-systems-pems-for-real

Nanyang Technological University

Research

JoVE Journal

Environment

28.0K Views.  Joint Research Centre. The European Commission has developed a Real-Driving Emissions (RDE) test procedure to verify pollutant emissions during real-world vehicle operation using the Portable Emissions Measurement Systems (PEMS). This paper presents the experimental procedures required by the newly-adopted RDE test.

Video: Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

Transient Gene Expression in Tobacco using Gibson Assembly and the Gene Gun

In order to target a single protein to multiple subcellular organelles, plants typically duplicate the relevant genes, and express each gene separately using complex regulatory strategies including differential promoters and/or signal sequences. Metabolic engineers and synthetic biologists interested in targeting enzymes to a particular organelle are faced with a challenge: For a protein that is to be localized to more than one organelle, the engineer must clone the same gene multiple times. This work presents a solution to this strategy: harnessing alternative splicing of mRNA. This technology takes advantage of established chloroplast and peroxisome targeting sequences and combines them into a single mRNA that is alternatively spliced. Some splice variants are sent to the chloroplast, some to the peroxisome, and some to the cytosol. Here the system is designed for multiple-organelle targeting with alternative splicing. In this work, GFP was expected to be expressed in the chloroplast, cytosol, and peroxisome by a series of rationally designed 5&#8217; mRNA tags. These tags have the potential to reduce the amount of cloning required when heterologous genes need to be expressed in multiple subcellular organelles. The constructs were designed in previous work11, and were cloned using Gibson assembly, a ligation independent cloning method that does not require restriction enzymes. The resultant plasmids were introduced into Nicotiana benthamiana epidermal leaf cells with a modified Gene Gun protocol. Finally, transformed leaves were observed with confocal microscopy.

This work describes a novel method for selectively targeting subcellular organelles in plants, assayed using the BioRad Gene Gun.

In order to target a single protein to multiple subcellular organelles, plants typically duplicate the relevant genes, and express each gene separately ...

A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsaturated parts of the soil, mycelia have been shown to overcome bioavailability limitations by actively transporting and mobilizing organic compounds over the range of centimeters. Whereas the extent of mycelia-based transport can be quantified easily by chemical means, verification of the contaminant-bioavailability to bacterial cells requires a biological method. Addressing this constraint, we chose the PAH fluorene (FLU) as a model compound and developed a water unsaturated model microcosm linking a spatially separated FLU point source and the FLU degrading bioreporter bacterium Burkholderia sartisoli RP037-mChe by a mycelial network of Pythium ultimum. Since the bioreporter expresses eGFP in response of the PAH flux to the cell, bacterial FLU exposure and degradation could be monitored directly in the microcosms via confocal laser scanning microscopy (CLSM). CLSM and image analyses revealed a significant increase of the eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU thus indicating FLU bioavailability to bacteria after mycelia-mediated transport. CLSM results were supported by chemical analyses in identical microcosms. The developed microcosm proved suitable to investigate contaminant bioavailability and to concomitantly visualize the involved bacteria-mycelial interactions.

A whole cell bioreporter assay with Burkholderia sartisoli RP037-mChe was developed to detect fractions of an organic contaminant (i.e., fluorene) available for bacterial degradation after active transport by mycelia bridging air-filled pores in a water unsaturated model system.

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is ...

A New Application of the Electrical Penetration Graph (EPG) for Acquiring and Measuring Electrical Signals in Phloem Sieve Elements

Electrophysiological properties of cells are often studied in vitro, after dissociating them from their native environments. However, the study of electrical transmission between distant cells in an organism requires in vivo, artifact-free recordings of cells embedded within their native environment. The transmission of electrical signals from wounded to unwounded areas in a plant has since long piqued the interest of botanists. The phloem, the living part of the plant vasculature that is spread throughout the plant, has been postulated as a major tissue in electrical transmission in plants. The lack of suitable electrophysiological methods poses many challenges for the study of the electrical properties of the phloem cells in vivo. Here we present a novel approach for intracellular electrophysiology of sieve elements (SEs) that uses living aphids, or other phloem-feeding hemipteran insects, integrated in the electrical penetration graph (EPG) circuit. The versatility, robustness, and accuracy of this method made it possible to record and study in detail the wound-induced electrical signals in SEs of central veins of the model plant Arabidopsis thaliana1. Here we show that EPG-electrodes can be easily implemented for intracellular electrophysiological recordings of SEs in marginal veins, as well as to study the capacity of SEs to respond with electrical signals to several external stimuli. The EPG approach applied to intracellular electrophysiology of SEs can be implemented to a wide variety of plant species, in a large number of plant/insect combinations, and for many research aims.

A New Application of the Electrical Penetration Graph EPG for Acquiring and Measuring Electrical Signals in Phloem Sieve Elements

Electrical Penetration Graph (EPG) is a well-established technique for studying the feeding behavior of stylet-bearing insects. Here we show a new application of EPG as a non-invasive tool for the acquisition of intracellular electrophysiology recordings of sieve elements (SEs), the cells that form the phloem vasculature in plants.

Electrophysiological properties of cells are often studied in vitro, after dissociating them from their native environments. However, the study of ...

The Use of an Automated System (GreenFeed) to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during storage. These processes are the major sources of greenhouse gas (GHG) emissions from animal production systems. Techniques for measuring enteric CH4 vary from direct measurements (respiration chambers, which are highly accurate, but with limited applicability) to various indirect methods (sniffers, laser technology, which are practical, but with variable accuracy). The sulfur hexafluoride (SF6)&#160;tracer gas method is commonly used to measure enteric CH4 production by animal scientists and more recently, application of an Automated Head-Chamber System (AHCS) (GreenFeed, C-Lock, Inc., Rapid City, SD), which is the focus of this experiment, has been growing. AHCS is an automated system to monitor CH4 and carbon dioxide (CO2) mass fluxes from the breath of ruminant animals. In a typical AHCS operation, small quantities of baiting feed are dispensed to individual animals to lure them to AHCS multiple times daily. As the animal visits AHCS, a fan system pulls air past the animal&#8217;s muzzle into an intake manifold, and through an air collection pipe where continuous airflow rates are measured. A sub-sample of air is pumped out of the pipe into non-dispersive infra-red sensors for continuous measurement of CH4 and CO2 concentrations. Field comparisons of AHCS to respiration chambers or SF6 have demonstrated that AHCS produces repeatable and accurate CH4 emission results, provided that animal visits to AHCS are sufficient so emission estimates are representative of the diurnal rhythm of rumen gas production. Here, we demonstrate the use of AHCS to measure CO2 and CH4 fluxes from dairy cows given a control diet or a diet supplemented with technical-grade cashew nut shell liquid.

The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Accuracy and precision of the techniques used to measure methane emissions from ruminant animals are critically important for the success of greenhouse gas mitigation efforts. This manuscript describes the principles and operation of an automated system to monitor methane and carbon dioxide mass fluxes from the breath of ruminant animals.

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during ...

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% fine dust formation within the EU15. But NH3 emissions also mean a considerable loss of nutrients. Many studies on NH3 emission from organic and mineral fertilizer application have been performed in recent decades. Nevertheless, research related to NH3 emissions after application fertilizers is still limited in particular with respect to relationships to emissions, fertilizer type, site conditions and crop growth. Due to the variable response of crops to treatments, effects can only be validated in experimental designs including field replication for statistical testing. The dominating ammonia loss methods yielding quantitative emissions require large field areas, expensive equipment or current supply, which restricts their application in replicated field trials. This protocol describes a new methodology for the measurement of NH3 emissions on many plots linking a simple semi-quantitative measuring method used in all plots, with a quantitative method by simultaneous measurements using both methods on selected plots. As a semi-quantitative measurement method passive samplers are used. The second method is a dynamic chamber method (Dynamic Tube Method) to obtain a transfer quotient, which converts the semi-quantitative losses of the passive sampler to quantitative losses (kg nitrogen ha-1). The principle underlying this approach is that passive samplers placed in a homogeneous experimental field have the same NH3 absorption behavior under identical environmental conditions. Therefore, a transfer co-efficient obtained from single passive samplers can be used to scale the values of all passive samplers used in the same field trial. The method proved valid under a wide range of experimental conditions and is recommended to be used under conditions with bare soil or small canopies (&#60;0.3 m). Results obtained from experiments with taller plants should be treated more carefully.

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Ammonia emissions are a major threat to the environment by eutrophication, soil acidification and fine particle formation and stem mainly from agricultural sources. This method allows ammonia loss measurements in replicated field trials enabling statistical analysis of emissions and of relationships between crop development and emissions.

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% ...

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and detritus, and excreting particulate and dissolved compounds, they serve as important agents for benthic-pelagic coupling. Accurately measuring the compounds removed and excreted by suspension feeders (such as sponges, ascidians, polychaetes, bivalves) is crucial for the study of their physiology, metabolism, and feeding ecology, and is fundamental to determine the ecological relevance of the nutrient fluxes mediated by these organisms. However, the assessment of the rate by which suspension feeders process particulate and dissolved compounds in nature is restricted by the limitations of the currently available methodologies. Our goal was to develop a simple, reliable, and non-intrusive method that would allow clean and controlled water sampling from a specific point, such as the excurrent aperture of benthic suspension feeders, in situ. Our method allows simultaneous sampling of inhaled and exhaled water of the studied organism by using minute tubes installed on a custom-built manipulator device and carefully positioned inside the exhalant orifice of the sampled organism. Piercing a septum on the collecting vessel with a syringe needle attached to the distal end of each tube allows the external pressure to slowly force the sampled water into the vessel through the sampling tube. The slow and controlled sampling rate allows integrating the inherent patchiness in the water while ensuring contamination free sampling. We provide recommendations for the most suitable filtering devices, collection vessel, and storing procedures for the analyses of different particulate and dissolved compounds. The VacuSIP system offers a reliable method for the quantification of undisturbed suspension feeder metabolism in natural conditions that is cheap and easy to learn and apply to assess the physiology and functional role of filter feeders in different ecosystems.

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and ...

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Nitrogen oxides (NOx = NO + NO2) are a family of atmospheric trace gases that have great impact on the environment. NOx concentrations directly influence the oxidizing capacity of the atmosphere through interactions with ozone and hydroxyl radicals. The main sink of NOx is the formation and deposition of nitric acid, a component of acid rain and a bioavailable nutrient. NOx is emitted from a mixture of natural and anthropogenic sources, which vary in space and time. The collocation of multiple sources and the short lifetime of NOx make it challenging to quantitatively constrain the influence of different emission sources and their impacts on the environment. Nitrogen isotopes of NOx have been suggested to vary amongst different sources, representing a potentially powerful tool to understand the sources and transport of NOx. However, previous methods of collecting atmospheric NOx integrate over long (week to month) time spans and are not validated for the efficient collection of NOx in relevant, diverse field conditions. We report on a new, highly efficient field-based system that collects atmospheric NOx for isotope analysis at a time resolution between 30 min and 2 hr. This method collects gaseous NOx in solution as nitrate with 100% efficiency under a variety of conditions. Protocols are presented for collecting air in urban settings under both stationary and mobile conditions. We detail the advantages and limitations of the method and demonstrate its application in the field. Data from several deployments are shown to 1) evaluate field-based collection efficiency by comparisons with in situ NOx concentration measurements, 2) test the stability of stored solutions before processing, 3) quantify in situ reproducibility in a variety of urban settings, and 4) demonstrate the range of N isotopes of NOx detected in ambient urban air and on heavily traveled roadways.

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Previous work suggests that the nitrogen isotopic composition of atmospheric nitrogen oxides might distinguish the influence of different sources in the environment. We report on an automated, mobile, field-based method for the high collection efficiency of atmospheric NOx for N isotopic analysis at an hourly time resolution.

Nitrogen oxides (NOx = NO + NO2) are a family of atmospheric trace gases that have great impact on the environment. NOx concentrations directly influence ...

Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas industry faces continued scrutiny for methane emissions from across the supply chain, due to methane&#39;s relatively high global warming potential (25-84x that of carbon dioxide, according to the Energy Information Administration). Currently, a variety of techniques of varied uncertainties exists to measure or estimate methane emissions from components or facilities. Currently, only one commercial system is available for quantification of component level emissions and recent reports have highlighted its weaknesses.
In order to improve accuracy and increase measurement flexibility, we have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases based on transportation emissions measurement principles. The FFS is a modular system that consists of an explosive-proof blower(s), mass airflow sensor(s) (MAF), thermocouple, sample probe, constant volume sampling pump, laser based greenhouse gas sensor, data acquisition device, and analysis software. Dependent upon the blower and hose configuration employed, the current FFS is able to achieve a flow rate ranging from 40 to 1,500 standard cubic feet per minute (SCFM). Utilization of laser-based sensors mitigates interference from higher hydrocarbons (C2+). Co-measurement of water vapor allows for humidity correction. The system is portable, with multiple configurations for a variety of applications ranging from being carried by a person to being mounted in a hand drawn cart, on-road vehicle bed, or from the bed of utility terrain vehicles (UTVs). The FFS is able to quantify methane emission rates with a relative uncertainty of &#177; 4.4%. The FFS has proven, real world operation for the quantification of methane emissions occurring in conventional and remote facilities.

Design and Use of a Full Flow Sampling System FFS for the Quantification of Methane Emissions

We have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases from across the natural gas supply chain.

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas ...

Engineering

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future combustion engine vehicle technology may emit large amounts of sub-23 nm particles. The Horizon 2020 funded project DownToTen (DTT) developed a sampling and measurement method to characterize particle emissions in this currently unregulated size range. A PN measurement system was developed based on an extensive review of the literature and laboratory experiments testing a variety of PN measurement and sampling approaches. The measurement system developed is characterized by high particle penetration and versatility, which enables the assessment of primary particles, delayed primary particles, and secondary aerosols, starting from a few nanometers in diameter. This paper provides instruction on how to install and operate this Portable Emission Measurement System (PEMS) for Real Drive Emissions (RDE) measurements and assess particle number emissions below the current legislative limit of 23 nm.

Presented here is the DownToTen (DTT) portable emission measurement system to assess real driving automotive emissions of sub-23 nm particles.

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future ...

Additive Manufacturing-Enabled Low-Cost Particle Detector

As particles with a size of 1 &#181;m or smaller pose a severe health risk to the human body, the detection and regulation of particle emissions are of great importance. A large share of particulate emissions are emitted by the transport sector. Most of the commercially available particle detectors are bulky, very expensive, and need additional equipment. This paper presents a protocol to build and test a standalone particle detector that is small and cost-efficient. 
The focus of this paper lies in the description of the detailed construction manual with video and the sensor evaluation procedure. The computer-aided design model of the sensor is included in the supplemental material. The manual explains all the construction steps, from 3D printing to the fully operational sensor. The sensor can detect charged particles and is therefore suitable for a wide range of applications. A possible field of application would be soot detection from power plants, wildfires, industries, and automobiles.

Here, we present a protocol on how to build and test a simple but efficient low-cost particle detector.

As particles with a size of 1 &#181;m or smaller pose a severe health risk to the human body, the detection and regulation of particle emissions are of ...

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

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