On-road testing with Portable Emissions Measurement Systems (PEMS) : guidance note for light-duty vehicles.
Date: 2018-08-13
Institutions: Joint Research Centre
Subjects: air quality, combustion gases, energy research, motor vehicle pollution, reduction of gas emissions, research report, technical standard, testing, ultra-fine particle, user guide

On-road testing with Portable 
Emissions Measurement Systems 
(PEMS) 

Guidance note for 
light-duty vehicles 

Valverde Morales, V., Bonnel, P. 

2018 

EUR 29029 EN

 
 
This publication is a Technical report by the Joint Research Centre (JRC), the European Commission’s science 
and knowledge service. It aims to provide evidence-based scientific support to the European policymaking 
process. The scientific output expressed does not imply a policy position of the European Commission. Neither 
the European Commission nor any person acting on behalf of the Commission is responsible for the use that 
might be made of this publication. 

Contact information  
Name: Pierre Bonnel 
Address: European Commission, Joint Research Centre, Via E. Fermi 2749, I-21027, Ispra (VA) - Italy 
Email: pierre.bonnel@ec.europa.eu 
Tel.: +39 0332 785301 

JRC Science Hub 
https://ec.europa.eu/jrc 

JRC109812 

EUR 29029 EN 

PDF 

ISBN 978-92-79-77345-7 

ISSN 1831-9424 

doi:10.2760/08294 

Luxembourg: Publications Office of the European Union, 2018 

© European Union, 2018 

Reuse is authorised provided the source is acknowledged. The reuse policy of European Commission documents 
is regulated by Decision 2011/833/EU (OJ L 330, 14.12.2011, p. 39). 

For any use or reproduction of photos or other material that is not under the EU copyright, permission must be 
sought directly from the copyright holders. 

How to cite this report: Valverde Morales V and Bonnel P, On-road testing with Portable Emissions 
Measurement Systems (PEMS) - Guidance note for light-duty vehicles, EUR 29029 EN, Publications Office of the 
European Union, Luxembourg, 2018, ISBN 978-92-79-77345-7, doi:10.2760/08294, JRC109812 

All images © European Union 2018, except where sourced otherwise. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Contents 

Disclaimer ............................................................................................................ 1 

Acknowledgements ................................................................................................ 2 

1  Introduction ...................................................................................................... 3 

2  On-road emissions test with PEMS [What to measure and how to do it]? .................. 4 

3  Instrumentation performance requirements [Which instruments to use?] ................. 7 

3.1

  Introduction ................................................................................................ 7 

3.2

  Emissions measurements.............................................................................. 7 

3.3

  PEMS data reporting .................................................................................... 8 

4  Test preparation [How to select and prepare the vehicle for the test?] ..................... 9 

4.1

  Basic PEMS set-up ....................................................................................... 9 

4.2

  Vehicle selection and inspection ................................................................... 10 

4.3

  Vehicle information reporting ...................................................................... 12 

5  Test conditions [Under which conditions to test the vehicle?] ................................ 15 

5.1

  Test conditions .......................................................................................... 15 

5.2

  Selection of test routes for EU-RDE testing ................................................... 19 

5.3

  Recommendations to drivers ....................................................................... 19 

6  Test Protocol [How to conduct the test?] ............................................................ 21 

6.1

  Checks before the installation of the instruments in the vehicle ....................... 21 

6.2

  Installation of instruments (Detailed by PEMS component) .............................. 22 

6.3

  Pre-Test Procedures ................................................................................... 29 

6.4

  Test runs .................................................................................................. 33 

6.5

  Post-test................................................................................................... 34 

6.6

  Conclusion of Test Series (PEMS dismounting)............................................... 36 

7  Data screening [How to evaluate the quality of the measurements?]...................... 37 

7.1

  Introduction .............................................................................................. 37 

7.2

  Test data screening .................................................................................... 38 

7.3

  Verification of (DPF) regeneration event ....................................................... 40 

8  Data exchange files [How to report the test data?] .............................................. 41 

List of abbreviations and definitions ....................................................................... 44 

List of figures ...................................................................................................... 46 

List of tables ....................................................................................................... 47 

Annex: Criteria for vehicle selection and failed vehicles decision ................................ 48 

i 

 
Disclaimer 

This  guidance  note  provides  best  practices  for  the  preparation,  the  execution,  and  the 
follow-up of emissions tests that are conducted with PEMS on board of light-duty vehicles 
(LDV)  equipped  with  conventional  combustion  engines  (gasoline,  diesel,  CNG,  LPG),  in 
particular for testing vehicles according to the European RDE legislative requirements laid 
down  in  Regulations  (EU)  2017/1151,  2016/427,  2016/646,  2017/1154  and  the  last 
"RDE4"  package  approved  at  TCMV  on  May  3rd  2018  (Main  ACT,  Annex),  collectively 
referred to in this document as the EU-RDE LDV regulations. 

The document does not substitute the operation manuals of the instruments, safety rules 
and recommendations, and official regulatory texts regarding in-use emissions tests with 
PEMS. 

It is intended to facilitate the implementation of Regulation (EC) No 715/2007. It is itself 
not  legally  binding.  Any  authoritative  reading  of  the  law  should  only  be  derived  from 
Regulation (EC) 715/2007 itself and other applicable legal texts or principles, for example 
the  regulations  mentioned  above.  While  this  note  seeks  to  assist  authorities  and 
operators by presenting good practices for an effective implementation of the applicable 
law,  only  the  Court  of  Justice  of  the  European  Union  is  competent  to  authoritatively 
interpret Union legislation. 

  The  sections  containing  this  icon  are  related  to  documentation  and  data  exchange 

requirements. 

  The  sections  containing  this  icon  are  recommendations  for  a  safe  installation  and 

use of the PEMS instruments. 

1 

Acknowledgements 

The  authors  gratefully  acknowledge  ACEA,  AVL,  HORIBA,  JAMA,  MAHA,  SENSORS,  TÜV 
NORD,  TÜV  HESSEN,  UTAC,  and  the  European  Commission's  colleagues  at  the 
Directorate-General  for  Environment  (DG  ENV),  the  Directorate-General  for  Internal 
Market, Industry, Entrepreneurship and SMEs (DG GROW), and the Joint Research Centre 
(JRC)  for  their  helpful  and  constructive  comments  that  significantly  contributed  to 
improve the final version of this PEMS guidance note. In addition, the authors would also 
like to thank AVL, HORIBA, MAHA, SENSORS, and the JRC Vehicle Emissions Laboratory 
(VELA) personnel for providing pictures to illustrate the document. 

Authors 

Víctor Valverde Morales 

Pierre Bonnel 

2 

 
1  Introduction 

This  document  provides  practical  recommendations  for  the  execution  of  real-driving 
emissions (RDE) tests with Portable Emissions Measurement Systems (PEMS) on board of 
light-duty  vehicles  (LDV)  in  the  European  context.  The  best  practices  contained  in  this 
guidance  note  aim  at  obtaining  valid  PEMS  tests  and  to  prevent  wrongdoings  in  the 
preparation, execution, and follow up of emissions testing with PEMS. Three main types 
of  PEMS  tests  can  be  envisaged.  Different  sets  of  requirements  and  recommendations 
apply to each of them: 

• 

• 

"Official"  EU-RDE  tests  conducted  during  new  vehicle  type  approvals  (EU-RDE-
TA); 
"Official" EU-RDE tests conducted on in-service vehicles with a certain mileage for 
in-service conformity testing (EU-RDE-ISC); 

•  Other  types  of  PEMS  tests,  not  according  to  the  EU-RDE  LDV  regulations,  and 
conducted  for  other  than  the  two  purposes  mentioned  above  (e.g.  vehicle 
development, emission factor development, defeat device screening, etc.). 

Table  1  summarises  the  applicable  set  of  requirements  for  each  type  of  test  and  the 
major differences between them.  

Table 1. Types of PEMS tests on light-duty vehicles and requirements 

Requirements 

EU-RDE TA 

EU-RDE ISC 

Other PEMS testing 

Parameters to be measured 

Mandatory 

Mandatory 

RDE Recommended 
(Table 2, Table 3) 

Instrumentation performance 

Mandatory 

EFM mandatory 

No use of vehicle ECU 
for exhaust flow 
measurement 

Mandatory 

Possible use of vehicle 
ECU 

RDE Recommended 
(Table 4) 

Testing conditions 

Mandatory 

Mandatory 

Test execution 

Mandatory 

Mandatory 

Data evaluation 

Mandatory 

Mandatory 

To address specific 
needs 

To address specific 
needs 

To address specific 
needs 

3 

2  On-road emissions test with PEMS [What to measure and 

how to do it]? 

The list of mandatory test parameters to be measured during the RDE tests is according 
to the EU-RDE Regulation, Appendix 1, Section 3.2., and the list of parameters that shall 
be  checked  on  a  case-by-case  basis,  depending  on  the  vehicle  technology  and  the 
purpose of the test (type approval, in-service conformity, other PEMS testing) are shown 
in  Table  2  and  Table  3  (for  hybrid  electric  vehicles).  The  mandatory  parameters  are 
indicated  with  the  letter  M.  Optional  parameters  which  may  be  used  on  a  case-by-case 
basis  are  indicated  with  the  letter  O.  For  EU-RDE-TA  and  EU-RDE-ISC  testing,  test 
parameters shall be measured at a constant frequency of 1 Hz or higher and recorded at 
a  1Hz  frequency.  For  other  types  of  PEMS  testing  it  is  recommended  to  measure  and 
record test parameters at least at 1 Hz. 

In line with the definitions from the EU-RDE regulation: 

• 

• 

'Analyser'  means  any  measurement  device  that  is  not  part  of  the  vehicle  but 
installed  to  determine  the  concentration  or  the  amount  of  gaseous  or  particle 
pollutants. 

'Sensor' means any measurement device that is not part of the vehicle itself but is 
installed  to  determine  parameters  other  than  the  concentration  of  gaseous  and 
particle pollutants and the exhaust mass flow. 

When  performing  PEMS  tests  in  the  context  of  EU-RDE  LDV  regulations,  the 
measurement of THC is not required. All the information regarding THC measurement is 
intended  to  provide  basic  requirements  on  instrument  handling  for  research  purposes. 
Currently,  the  on-road  measurement  of  THC  is  performed  using  the  FID  measurement 
principle, which is based on the usage  of a gas mixture of  Hydrogen (40%) and Helium 
(60%). As this gas is categorized as extremely flammable and asphyxiant, it produces a 
high  safety  and  health  risk,  as  the  gas  cylinder  is  not  only  transported  but  used  with  a 
pressure  reduction  valve  installed  and  opened  in  the  passenger  cabin.  The  possibility  to 
use such pressurized gas cylinders in the cabin of the vehicle depends on the applicable 
health, safety and road regulations. 

From  a  technical  perspective,  the  use  of  THC  measurement  instruments  increases  the 
weight of the equipment by approximately 25% and it limits the flexibility in the use of a 
PEMS  due  to  its  larger  size.  In  addition,  as  the  sampling  system  (including  connectors, 
lines,  etc.)  must  be  heated  to  at  least  191  C  the  energy  demand  will  approximately 
double. Therefore, larger and heavier batteries must be installed. 

Table 2. Test parameters for all vehicles 

Unit 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Technique(8) 

Parameter 

CO2 concentration(1) 

CO concentration(1) 

NOX concentration(1, 11) 

PN concentration 

ppm 

ppm 

ppm 

#/m3 

Exhaust mass flow rate  

kg/s 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

O 

Analyser 

Analyser 

Analyser(7) 

Analyser 

EFM(10) 

4 

 
 
Test parameters for all vehicles (continued) 

Parameter 

Ambient humidity 

Ambient temperature 

Ambient pressure 

Vehicle speed 

Unit 

% 

K 

kPa 

km/h 

Vehicle latitude 

deg:min:s 

Vehicle longitude  

deg:min:s 

Vehicle altitude(9) 

Engine fuel flow(2) 

Engine intake air flow(2) 

Intake air flow temperature 

THC concentration(1,4) 

CH4 concentration(1,4) 

NMHC concentration(1,4) 

Exhaust gas temperature(5) 

Engine coolant 
temperature(5) 

Engine speed(5) 

m 

g/s 

g/s 

K 

ppm C1 

ppm C1 

ppm C1 

K 

K 

rpm 

EU-
RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Technique(8) 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

- 

- 

- 

M 

O 

O 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

- 

- 

- 

M 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

Sensor 

Sensor 

Sensor 

Sensor, GNSS, or ECU(3) 

GNSS 

GNSS 

GNSS or sensor 

Sensor or ECU 

Sensor or ECU 

Sensor or ECU 

Analyser 

Analyser 

Calculated(6) 

Sensor 

Sensor or ECU 

Sensor or ECU 

1  To  be  measured  on  a  wet  basis  or  to  be  corrected  as  described  in  point  8.1  of  Appendix  4  of 

Regulation 2016/427. 

2  To  be  determined  only  if  indirect  methods  are  used  to  calculate  exhaust  mass  flow  rate  as 

described in paragraphs 10.2 and 10.3 of Appendix 4 of Regulation 2016/427. 

3 The method to determine vehicle speed shall be chosen according to Appendix 1, point 4.7, of 

Regulation 2016/427. 

4  Parameter only  mandatory  if  measurement required by  Annex IIIA,  Section  2.1.  of Regulation 

2016/427. 

5 To be determined only if necessary to verify the vehicle status and operating conditions. 
6 Calculated from THC and CH4 concentrations according to point 9.2 of Appendix 4 of Regulation 

2016/427. 

7 May be calculated from measured NO and NO2 concentrations. 
8 Multiple parameter sources may be used. 
9 The preferable source is the ambient pressure sensor. GNSS is not recommended since loss of 

positional signal can lead to inaccurate altitude measurement. 

10  For  EU-RDE-TA,  the  exhaust  mass  flow  has  to  be  determined  by  measurement  equipment 
functioning  independently  from  the  vehicle  and  no  vehicle  ECU  data  shall  be  used  in  this 
respect. For EU-RDE-ISC or other PEMS tests, alternative methods to determine the exhaust 
mass flow can be used according to Appendix 2, Section 7.2 of Regulation 2016/427. 

11 NOx (nitric oxide: NO and nitrogen dioxide: NO2), expressed in NO2 equivalent 

5 

 
 
                                           
Test parameters for all vehicles (continued) 

Parameter 

Engine torque(5) 

Torque at driven axle(5) 

Pedal position(5) 

Fault status(5) 

Regeneration status(5) 

Engine oil temperature(5) 

Actual gear(5) 

Desired gear (e.g. gear 
shift indicator)(5) 

Unit 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Technique(8) 

Nm 

Nm 

% 

- 

- 

K 

# 

# 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

Sensor or ECU 

Rim torque meter 

Sensor or ECU 

ECU 

ECU 

Sensor or ECU 

ECU 

ECU 

Table 3. Test parameters specific to hybrid vehicles 

Parameter 

State of charge of the 
battery 

Hybrid battery current 

Hybrid battery voltage 

Remark: 

Unit 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Technique 

% 

A 

V 

O 

O 

O 

O 

O 

O 

O 

O 

O 

ECU 

ECU or power analyser 

ECU or power analyser 

Considering  that  an  incorrect  acquisition  of  GNSS  data  can  lead  to  an  invalidation  of  a 
trip  (wrong  calculation  of  trip  composition,  trip  dynamics,  elevation  gain,  etc.)  it  is 
recommended to duplicate the variables captured by the GNSS using other sensors (ECU 
speed,  ambient  pressure  sensor  to  derive  altitude,  optical  velocity  measurement 
systems, etc.).  

In particular for vehicle speed, Regulation 2016/427, Point 4.7, states that vehicle speed 
shall be determined by at least one of the following methods: GNSS, specific sensor (e.g. 
optical or micro-wave sensor), or ECU. The total trip distance calculated from the vehicle 
speed  measurements  cannot  deviate  between  instruments,  or  between  a  single 
instrument  and  the  distance  as  calculated  with  a  topographic  map,  by  more  than  4  %. 
The  recorded  vehicle  speed  is  subjected  to  a  consistency  check  according  to  Regulation 
2016/427, Appendix 4, point 7. When using a GNSS, it is possible to correct data gaps in 
the  vehicle  speed  signal  with  a  secondary  signal  as  long  as  it  does  not  exceed  an 
uninterrupted time period of 120 seconds or a total of 300 seconds. When using a sensor 
to calculate the vehicle acceleration, an accuracy  of 0,1 %  for all speed values above 3 
km/h and a sampling frequency of 1 Hz is required. 

6 

3  Instrumentation performance requirements [Which 

instruments to use?] 

3.1

  Introduction 

This section describes the equipment characteristics and their performance requirements. 
The  PEMS  systems  to  be  used  for  the  EU-RDE-TA  and  EU-RDE-ISC  testing  have  to 
comply  with  the  general  requirements  described  in  the  EU-RDE  LDV  regulations,  and 
have the following characteristics: 

•  To be small, lightweight and easy to install; 
•  To work with a low power consumption so that tests of at least 2.5-3 hours can be 

run with one set of batteries; 

•  To measure and record the concentrations of NOx (or NO and NO2), CO, CO2 gases 

and Particulate Number (PN) in the vehicle exhaust;  

•  To  measure  Exhaust  mass  flow  rate  of  the  vehicle  exhaust  (compulsory  on  EU-

• 

RDE-TA, optional on EU-RDE-ISC); 
In  case  of  other  PEMS  tests,  to  measure  and/or  record  the  relevant  parameters 
(engine data from the ECU, vehicle position from the GNSS, weather data, etc.). 

3.2

  Emissions measurements 

For  EU-RDE-TA  and  EU-RDE-ISC  tests,  the  performance  of  the  PEMS  equipment  to  be 
used  for  measuring  gaseous  emissions  and  particle  number  on  light-duty  vehicles  shall 
fulfil the requirements stated in the EU-RDE LDV regulations (Table 4). 

For  other  types  of  PEMS  testing,  it  is  recommended  to  use  commercially  available 
equipment fulfilling at least the same requirements. In case the equipment does not fulfil 
the requirements settled in Table 4, it is highly recommended to describe the equipment 
characteristics and a proof of technical suitability of the equipment in the results report. 

Table 4. Gas and PN analysers. RDE specifications and verification 

Item 

Reference(s) 

Analysers 
Specifications 

their 
EU-RDE  Regulations  2016/427,  2016/646,  2017/1151,  2017/1154  and 
amendments.  In  particular,  Regulation  2016/427,  Appendix  2  sets  the  specifications  for 
PEMS instrumentation: 

- Section 4 (Requirements for analysers measuring gas components) 

- Section 6 (Requirements for analysers measuring particle emissions) 

-  Section  7  (Specifications  for  instruments,  sensors  and  signals  for  measuring  exhaust 
mass flow) 

- Section 8 (Requirements for sensors measuring non-exhaust parameters) 

and other requirements, when applicable 

Analysers 
verification 

EU-RDE  Regulations  2016/427,  2016/646,  2017/1151,  2017/1154  and 
their 
amendments.  In  particular,  Regulation  2016/427,  Appendix  2  sets  limits  for  PEMS 
instrumentation verification: 

- Section 3 (Linearity verification) 

- Section 4 (Requirements for analysers measuring gas components) 

- Section 5 (Characteristics of calibration and span gases) 

- Section 6 (Requirements for analysers measuring particle emissions) 

and other requirements, when applicable 

7 

 
 
For  EU-RDE-TA  and  EU-RDE-ISC  tests,  the  Regulation  2016/427,  Appendix  3  describes 
the  procedure  for  validating  the  PEMS  equipment  (including  the  gas  and  PN  analysers, 
and  the  EFM)  installed  on  a  vehicle  under  transient  conditions,  preferably  with  the 
worldwide  harmonised  light  vehicles  test  cycle  (WLTC)  on  a  chassis  dynamometer.  The 
validation is the process of evaluating the correct installation and functionality of a PEMS 
and  the  correctness  of  exhaust  mass  flow  rate  measurements  as  obtained  from  one  or 
multiple Exhaust mass Flow Meters (EFM) or as calculated from sensors or ECU signals. 

It is highly recommended to validate the performance of the PEMS equipment after each 
new PEMS installation on a vehicle and either before and/or after each set of tests. It is 
suggested to follow the best practices for the validation exercise suggested in the ad-hoc 
report  of  the  Joint  Research  Centre1.  For  other  types  of  PEMS  testing,  it  is  also 
recommended to undergo the process of PEMS validation as described for EU-RDE tests. 

3.3

  PEMS data reporting 

 For EU-RDE-TA and EU-RDE-ISC tests, the parameters to be recorded and reported 
are  specified  by  the  EU-RDE  Regulation,  Appendix  8  (e.g.  PEMS  manufacturer,  PEMS 
type, PEMS serial number, Gas analyser type, EFM type, etc.). The list of mandatory and 
optional  parameters  is  indicated  in  Appendix  8  together  with  the  compulsory  format  for 
data  exchange.  The  last  section  of  the  present  document  provides  a  short  overview  of 
the formatting requirements and potential issues. 

1 Recommendations for the validation of PEMS in the laboratory (under development) 

8 

 
 
                                           
4  Test preparation [How to select and prepare the vehicle 

for the test?] 

4.1

  Basic PEMS set-up 

For  EU-RDE-TA,  EU-RDE-ISC,  and  other  types  of  PEMS  testing,  the  installation  of  the 
equipment  shall  be  conducted  according  to  the  applicable  health,  safety  and  road 
regulations.  The  main  components  of  the  PEMS  should  be  installed  in  the  following 
manner: 

• 

  The  main  unit  containing  the  analysers  to  measure  gaseous  emissions 
and/or  PN,  as  well  as  the  PEMS  control  unit,  can  be  installed  either  inside  or 
outside the vehicle according to the specifications of the instruments supplier. The 
installation  of  the  PEMS  equipment  inside  the  vehicle  (Figure  1,  left)  has  to  be 
conducted according to the applicable safety regulations, particularly in relation to 
the protection of the driver (the installation has to be made in such a way that the 
exhaust gas does not leave the analyser and sampling lines due to leakages, and 
the components  of the  PEMS must be safely attached). The PEMS in the exterior 
of the vehicle can be placed on a tow bar or a hook using a platform (Figure 1, 
right)  and  should  include  an  appropriate  warning  sign  for  other  drivers.  Either 
inside  or  outside  the  vehicle,  the  PEMS  equipment  should  be  installed  in  such  a 
way  to  minimise  excessive  vibrations  (caused  road  condition/driving  style,  etc.), 
heating, electromagnetic interferences, shocks and exposure to dust. 

•  For direct exhaust flow measurements the exhaust flow meters must be attached 
to  the  vehicle’s  tailpipe  according  to  the  recommendations  of  the  PEMS 
manufacturer and at least one additional fixation point. Exhaust pipe adaptors or 
junctions  shall  not  adversely  affect  the  operation  of  the  engine  or  exhaust  after-
treatment systems. A simple rule to select the EFM diameter is to have it at least 
as  the  tailpipe  diameter  to  avoid  backpressure.  An incorrect  diameter  size  of  the 
EFM  may  result  in  DPF/  GPF  malfunction  and  a  risk  in  engine  damage  (e.g. 
turbocharger  over  speed,  exhaust  valves  keeping  open,  etc.).  Avoid  abrupt 
diameter  changes  and  leave  enough  straight  tube  before  the  flow  sensing 
elements. 
In  case  the  PEMS  test  allows  the  use  of  the  ECU,  the  interface  of  the  ECU  data 
acquisition  modules  might  be  connected  to  the  appropriate  vehicle  interfaces, 
typically a CAN bus. It is forbidden to connect the ECU during an official EU-RDE-
TA test to measure the exhaust flow. 

• 

•  The GNSS antenna should be installed at the highest point of the vehicle. In case 
this is not possible (e.g., convertibles with fabric top) it is recommended to clamp 
it to the side window. The weather station should be installed on the body of the 
vehicle in a location where it minimises its aerodynamic drag, and where it cannot 
be  affected  by  exhaust  gas.  Preferably  install  the  equipment  close  to  a  vehicle 
opening (window, boot, etc.). 

Further  details  and  recommendations  for  the  installation  of  the  PEMS  components  are 
detailed in chapter 6. 

9 

 
 
Figure 1. Installation of PEMS main units 
left) inside the vehicle right) outside the vehicle 

Source: left) JRC VELA lab right) Sensors, Inc. 

4.2

  Vehicle selection and inspection 

A  general  verification  of  the  correct  technical  functioning  of  the  test  vehicle  shall  be 
carried  out  before  any  PEMS  test.  The  performance/maintenance  inspections  of  the  test 
vehicle  have  to  be  performed  prior  to  the  installation  of  the  PEMS  equipment.  Any 
identified problem must be documented and solved before testing. 

In addition, a safety inspection of the vehicle must be conducted prior to any test. Some 
safety related issues to be checked are for instance: 

• 

• 

  The  equipment  mounted  outside  of  vehicles,  e.g.  the  EFM  on  the  vehicle 

tailpipe or the whole PEMS unit, which might require appropriate warning signs. 

  For  safety  reasons,  the  equipment  inside  the  vehicle  shall  be  properly 

secured (e.g. holding straps to secure the batteries and load). 
•  Adequate routing of tubes, cables, and the heated exhaust line. 
•  Check  for  the  presence  of  hot  surfaces  and  sharp  edges,  take  appropriate  action 

to avoid injuries, and signal if needed. 

• 

 When applicable, make sure that the installation of pressurised gas cylinders 
(e.g. for the FID fuel inside the vehicles) or power sensors on hybrid vehicles are 
properly  secured.  The  use  of  burnable  substances  on  a  PEMS  test  (like  the  FID-
gas) has to be checked by the responsible safety services in every case. 

More  specifically  for  EU-RDE-TA  and  EU-RDE-ISC  tests1,  the  following  vehicle 
selection criteria shall apply (non-exhaustive): 

•  For RDE-TA tests, the vehicle shall be in good mechanical condition and shall have 
been  run  in  and  driven  at  least  3  000  km  before  the  test.  The  running-in  of  the 
vehicle shall use all available components of the vehicle. 

•  For RDE-ISC testing the vehicle shall have been in service for at least 15 000 km 
and  for  no  more  than  100  000  km.  In  addition,  and  since  the  date  of  its  first 
registration, the vehicle must be between 6 months and 5 years old. 

•  The vehicle must be registered in the EU. 
•  The  vehicle  maintenance  and  operational  records  shall  be  available  (i.e.  all 

maintenance has to be performed by authorised dealerships). 

1 Details available in RDE regulation, Annex II - Part B (New In-Service Conformity Methodology), Appendix 1 

(Criteria for vehicle selection and failed vehicles decision) 

10 

 
 
                                           
•  A  visual  inspection  shall  check  for  the  presence  of  obstructed  air  paths  (intake 
system),  potentially  damaged  exhaust  system,  damaged  components  and 
tampering systems. 

•  Any  kind  of  tuning  or  traces  of  tuning  (body  of  the  vehicle,  electrical  or 
electronics)  by  the  vehicle  owner  would  make  the  vehicle  not  eligible  for  official 
RDE testing. 

•  Roof  boxes  or  objects  on  top  of  the  vehicle  that  may  impact  its  frontal  area  and 
which  may  have  an impact  on  the  aerodynamic  characteristics  of  the  vehicle  are 
not  allowed  (other  than  measuring  equipment,  i.e.  GNSS  antenna  that  should 
have the minimum possible cross-section surface) (Figure 2). 

•  Using  a  trailer  hook  for  installing  the  PEMS  is  permitted  but  the  vehicle’s  power 
supply  must  not  be  connected  or  used  for  the  PEMS  equipment.  It  is  permitted 
however,  to  power  any  safety-related  illumination  of  fixtures  (like  licence  plate 
lights  and  safety  indicators)  by  the  vehicle's  battery,  as  stated  in  point  3.4.6  of 
Appendix I of Regulation 2016/646. 

•  Towing a trailer is not possible since it will have an important impact on the test 
mass. However, light trailers such as a wheel rotational speed sensors to measure 
vehicle  speed  is  allowed  as  long  as  the  trip  requirements  in  the  RDE  Regulation 
can  be  fulfilled  (speed,  acceleration,  payload,  etc.)  and  it  remains  within  the 
manufacturers  recommendations  for  the  use  of  trailers.  The  maximum  support 
load of the rear-suspension must not be exceeded for safety reasons. 

•  The  tyre  types  and  pressure  shall  be  according  to  the  vehicle  manufacturer's 
recommendations. The tyres shall have tread depth as recommended by customer 
safety associations (i.e. at least 3mm of tread depth for summer tyres and 4 mm 
for winter tyres). 

•  The vehicle physical configuration as described under the points above should not 
be  modified  during  a  test  (i.e.  changing  the  tyre  pressure  during  an  on-going 
PEMS test is not allowed). 

• 

•  A  vehicle  whose  operating  fluids  (i.e.  lubricant,  coolant,  urea,  and  fuel)  do  not 
follow the vehicle manufacturer's  recommendations is not eligible for official RDE 
tests. 
In  the  case  of  an  RDE  test  with  a  failed  result,  samples  of  fuel,  lubricant  and 
reagent (if applicable) shall be taken and kept for at least 1 year under conditions 
guaranteeing  the  integrity  of  the  sample.  Once  analysed,  the  samples  can  be 
discarded. 

•  For diesel vehicles: if the urea tank level does not guarantee the completion of the 
RDE testing, the reagent must be refilled prior to testing. Warnings/reagent level 
in the dashboard shall be checked prior the test. 

•  For  RDE  tests,  the  vehicle  On-Board  Diagnostics  (OBD)  shall  be  checked  and 
documented  at  the  selection  stage.  Any  issue,  as  listed  in  Table  5,  makes  the 
vehicle not eligible for RDE testing. 

•  For RDE-ISC testing, vehicles used for racing/motor sport are not eligible. 

For  EU-RDE-ISC,  the  complete  list  of  criteria  for  vehicle  selection  and  failed  vehicles 
decision can be found in the Annex. 

Table 5. List of OBD issues making the vehicle non-eligible for RDE-TA and RDE-ISC tests 

Item 

Fault memory (Mode 7, Mode 3) 

Visual check of the MIL. MIL-Status 

If any red or orange alarm lights are present on the dashboard, the vehicle may not be eligible 

The test shall not to be performed when the SCR system is under driver warning system. 

11 

4.3

  Vehicle information reporting 

 For EU-RDE-TA and EU-RDE-ISC tests there is a fixed set of mandatory parameters 
of the vehicle to be recorded (specified by the EU-RDE LDV regulations) indicated with an 
M  in  Table  6.  Additional  recommended  parameters  to  be  recorded  on  a  case-by-case 
basis  for  EU-RDE-TA  and  EU-RDE-ISC  tests,  and  other  PEMS  testing,  are  indicated  with 
the letter O. The testing conditions to be recorded are specified in Table 10. 

Table 6. Vehicle information to be reported 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

Vehicle type 

[Vehicle commercial name] 

Vehicle manufacturer 

[name] 

Vehicle model year 

[year] 

Vehicle ID 

[VIN code as defined in ISO 
3779:2009] 

Odometer value at test start 

[km] 

Odometer value at test end 

[km] 

Vehicle category 

[category as defined in Annex II to 
Directive 70/156/EEC] 

Type approval emissions norm 

[Euro X] 

Ignition type 

[SI/CI] 

Engine rated power 

Peak torque 

Engine displacement 

[kW] 

[Nm] 

[ccm] 

Transmission 

[manual/ automatic/ CVT] 

Number of forward gears 

[#] 

Fuel type. If flexifuel indicate 
fuel used in the test 

[gasoline/ diesel/LPG / NG] 

Lubricant 

[product label] 

Front and rear tyre size(3) 

[width.height.rim.diameter] 

Front and rear axle tyre 
pressure 

[bar/bar] 

Road load parameters 

[F0/F1/F2] 

Type-approval test cycle 

[NEDC/WLTC] 

Type-approval CO2 emissions 

[g/km] 

CO2 emissions in WLTC mode 
Low 

[g/km] 

12 

Vehicle information to be reported (continued) 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

CO2 emissions in WLTC mode 
Mid 

[g/km] 

CO2 emissions in WLTC mode 
High 

[g/km] 

CO2 emissions in WLTC mode 
Extra High 

[g/km] 

Vehicle test mass(2) 

[kg] 

Propulsion Type 

[ICE/NOVC-HEV/ OVC-HEV] 

Wheel drive mode 

[2WD/4WD] 

Electric motor power 

[kW. 0 if vehicle with ICE only] 

Engine condition at test start 

[cold/warm] 

Artificial payload 

[% deviation from the payload] 

Fuel used  

[reference/market/EN228] 

Tyre tread depth  

[mm] 

Vehicle age 

[months] 

Is the vehicle equipped with 
start-stop technology? 

[Yes, No] 

Is the vehicle equipped with a 
particle filter? 

[Yes, No] 

Is the vehicle equipped with 
SCR technology? 

[Yes, No] 

Is the vehicle equipped with 
EGR technology? 

[Yes, No] 

Is the vehicle equipped with LNT 
technology? 

[Yes, No] 

13 

 
 
Figure 2. Vehicles equipped with a roof box (left) or loaders that modify the aerodynamic 
characteristics of a vehicle (right) are not eligible for RDE-TA and RDE-ISC testing. 

Source: left) FREE PLAST srl.; right) Enganches y Remolques Aragón s.l. 

14 

 
5  Test conditions [Under which conditions to test the 

vehicle?] 

5.1

  Test conditions 

For EU-RDE-TA, and EU-RDE-ISC testing, the test conditions must fulfil the requirements 
of the RDE-LDV  regulations. The main requirements are  shown in Table 7. For EU-RDE-
ISC testing it is recommended to select the boundary conditions of the different RDE trips 
within a given sample in a way as to cover the distribution of driving situations under real 
life  operation  in  a  representative  way.  For  other  types  of  PEMS  testing,  anything  is  in 
principle possible, provided that the testing conditions do not compromise safety and the 
PEMS instrumentation functioning. 

Recommendations and 
suggestions for other 
PEMS tests 

When the duration is 
greater than 120 minutes, 
attention shall be paid to 
the risk of instrumentation 
drift and automated zero-
checks of the measurement 
equipment are 
recommended. The power 
supply must be set 
accordingly to the trip 
duration.  

Any temperature (coolant, 
oil) may be used for 
checking the conditioning of 
the combustion engine. 
When the ECU signals are 
being monitored, it is 
possible to consider the 
engine as warm when the 
engine coolant temperature 
is above 70 ºC. 

A trip with any combination 
containing varying 
percentages of urban, rural 
and motorway driving is 
permitted. The vehicle 
velocity may exceed 145 
km/h in roads where this is 
permitted (e.g. motorways 
with no speed limit) 
according with other legal 
limits. 

Table 7. Overview of testing conditions 

Condition 

EU-RDE-TA & EU-RDE-ISC requirements 

Test duration 

90 to 120 minutes 

Engine start 

In  order  to  assess  the  emissions  during  trips  in  hot  start,  a 
certain number of vehicles per PEMS test family shall be tested 
without conditioning but with a warm engine. An engine can be 
considered  as  warm  when  the  engine  coolant  temperature 
and/or engine oil temperature is above 70 ºC. 

Test route 
requirements 
- Urban, rural 
and 
motorway 
definitions 
and shares 

- Urban, rural and motorway driving defined by speed:  

City: ≤ 60 km/h 
Rural: >60 km/h and ≤ 90 km/h 
Highway: >90 km/h 

For N2 vehicles with a device limiting speed to 90 km/h: 

Rural: >60 km/h and ≤ 80 km/h 
Highway: >80 km/h 

- Urban, rural and motorway driving minimum distance: 16 km 

- Distance shares: 

City: ≥29% and ≤ 44 % 
Rural: ≥23% and ≤ 43 % 
Highway: ≥23% and ≤ 43 % 

The vehicle velocity shall normally not exceed 145 km/h. This 
maximum speed may be exceeded by a tolerance of 15 km/h 
for not more than 3 % of the time duration of the motorway 
driving. Local speed limits remain in force at a PEMS test, 
notwithstanding other legal consequences. 

15 

 
 
Test route 
requirements 
- Average 
speed and 
stop times 

Ambient 
conditions – 
Temperature 

Overview of testing conditions (continued) 

Condition 

EU-RDE-TA & EU-RDE-ISC requirements 

Recommendations and 
suggestions for other 
PEMS tests 

- Urban average speed: ≥15 km/h and ≤ 40 km/h 

- Cold start average speed including stops: ≥15 km/h and ≤ 40 
km/h 

- Cold start maximum speed ≤ 60 km/h 

No requirements. 

- Stop periods (when vehicle speed < 1km/h) shall account for 6 – 
30% of time duration of urban phase. No stop shall exceed 300 
seconds or the trip will be voided. 

- Stop period during cold start ≤ 90 seconds 

- Moderate: ≥ 0°C and ≤ 30°C 

- Extended: (≥ -7°C and < 0°C) or (> 30°C and ≤ 35°C) 

Derogation limits(1):  

- Moderate: 3°C to 30°C 

- Extended: -2°C to <3°C and >30°C to 35°C 

Ambient 
conditions – 
Altitude 

- Moderate: ≤ 700 m above sea level 

- Extended: >700 m and ≤ 1300m above sea level 

- Maximum altitude difference between start and end point: 100 m 

- Maximum cumulative altitude gain: 1200 m per 100km. Valid for 
both the urban and total trip. 

The manufacturers 
recommended 
temperatures of use for 
analysers and sensors 
must not be exceeded. 

Attention shall be paid to 
potential and automated 
altitude corrections in the 
instruments, which might 
not be applicable outside 
the RDE ranges. The 
manufacturers 
recommended pressures 
of use for analysers and 
sensors must not be 
exceeded. 

Road 
condition 

EU-RDE-TA and EU-RDE-ISC cannot be performed on unpaved 
roads.  

Same as for EU-RDE 
recommended. 

In addition, even though the EU-RDE LDV regulations do not 
specify this point, common sense and safety recommend avoiding 
extreme weather conditions (mud, icy roads, and fresh snow). 

Fuel, 
lubricating 
oil, reagent 

Vehicles must be run using market fuel, oil, and reagent, always 
following the recommendations of the vehicle's manufacturer. 

It is required to collect a sample of the test fuel(s), oil and 
reagent(s) for EU-RDE tests whenever the emissions are above the 
NTE limit. 

Follow the 
recommendations of the 
vehicle's manufacturer. 

Driving Time 

Tests should be conducted during normal working days (Monday to 
Friday). Recommended hours range from 7am to 8pm. 

No requirements. 

Vehicle 
payload 

The vehicle's basic payload shall comprise the driver, a witness of 
the test (if applicable) and the test equipment, including the 
mounting and the power supply devices. The total shall not exceed 
90% of the vehicle's permissible payload. 

The total payload shall 
not exceed 100% of the 
vehicle's permissible 
payload. The maximum 
load per axle should not 
be exceeded. 

1Derogation limits apply 

Vehicles of categories M1 and 

Vehicles of category N1 (class II and III) and 

until 

M2 

New types of vehicle 
New vehicles 
Vehicle categories defined in Annex II to Directive 2007/46/EC 

01 January 2020 
01 January 2021 

category N2 
01 January 2021 
01 January 2022 

16 

                                           
Recommendations and 
suggestions for other 
PEMS tests 

Same as for EU-RDE 
recommended.  

Same as for EU-RDE. 

Same as for EU-RDE. 

Overview of testing conditions (continued) 

Condition 

EU-RDE-TA & EU-RDE-ISC requirements 

Vehicle pre-
conditioning 

Vehicle air-
conditioning 
and auxiliary 
devices 

Vehicle gear 
shift and 
operating 
modes 

Before an EU-RDE-TA or EU-RDE-ISC test, the vehicle has to be 
driven for at least 30 minutes, parked with doors and bonnet 
closed and kept in engine-off status between 6 and 56 hours 
within moderate or extended altitude and temperatures 
conditions. Soaking temperature 3 hours prior to the test must 
be recorded. 

It is recommended to drive in normal roads and at least 20 to 
25 minutes on the motorway to limit the risk of regeneration of 
the DPF during the actual test. 

In general terms, the recommendations regarding the use of 
vehicle air-conditioning, auxiliary devices, payload, road 
condition, gear shifting, tyre conditions and the driver behaviour 
apply to the pre-conditioning drive. 

When several EU-RDE tests are conducted in consecutive days, 
the previous day EU-RDE test can be used as pre-conditioning 
drive for the current day test. 

Problems identified during the pre-conditioning and the total 
soaking time should be reported. 

It is not necessary to make use of the PEMS instruments during 
the pre-conditioning drive. However, its use is encouraged to 
identify potential problems with the instrumentation 
performance or in the recording that may prevent/delay the 
actual EU-RDE test. During the parking in low temperatures it 
might be wise to heat the PEMS equipment using an external 
source in order to avoid issues of condensation.  

For a hot EU-RDE test, the vehicle shall be driven to reach an 
engine oil or engine coolant temperature above 70C. Then the 
engine shall be stopped, and the pre-test shall be performed 
(calibration of PEMS system).  

The air conditioning system or other auxiliary devices can be 
operated in a way which corresponds to their possible use by a 
consumer at real driving on the road. Any misuse of the air-
conditioning system should be avoided, such as for instance 
using it with open windows, if not needed for the measuring 
equipment. The recommended temperature for the comfort of 
the passenger(s) is in the range of 20 to 24°C. 

All original auxiliary devices available to the user are allowed 
(i.e. only original devices from the Manufacturer). Any use shall 
be documented. Electrical auxiliaries that are automatically 
shut-down when their goal is achieved (i.e. rear window 
heating, mirror heating, etc.) should only be re-started again if 
actually needed for a safe driving. 

When several gear shift and/or vehicle operating modes are 
available the vehicle can be tested under any mode: eco, 
standard, sport, etc. with the exception of the off-road modes 
(for non-paved roads). It is however recommended to use the 
predominant mode, including the D (drive) mode for automatic 
transmissions. OVC-HEVs vehicles may be tested in any 
selectable mode (charge depleting, charge sustaining), including 
battery charge mode. 

In case a vehicle has a "race" mode, to be used only on test 
tracks, this mode shall not be used for EU-RDE testing, as safety 
features might be disabled.  

It is strongly recommended not to disable safety related vehicle 
modes (e.g. ABS, DSC, ADM, ESP, etc.) in case the test is 
carried by non-professional drivers. 

17 

Overview of testing conditions (continued) 

Condition 

EU-RDE-TA & EU-RDE-ISC requirements 

Recommendations and 
suggestions for other 
PEMS tests 

Vehicle 
battery 

Vehicles should not be tested with an empty battery. In case the 
vehicle has problems starting, the battery may be replaced 
following the recommendations of the vehicle's manufacturer. 
The vehicle shall then be pre-conditioned as indicated above 
and tested. 

It is possible to charge the battery prior to the pre-conditioning 
but not before the start of an EU-RDE-TA or EU-RDE-ISC tests. 

Vehicles should not be 
tested with an empty/faulty 
battery. In case it is 
needed, the battery may be 
charged/replaced prior the 
vehicle conditioning. 

The tyre types and pressure shall be according to the vehicle's 
manufacturer recommendations. The tyre pressure shall be 
checked prior to the pre-conditioning and adjusted to the 
recommended values if needed. 

Vehicle tyres 

The tyre profile depth should be verified according to the 
recommendations of customer safety associations (e.g. ADAC), 
but should have at least 3mm of tread depth for summer tyres 
and 4 mm for winter tyres. 

Same as for EU-RDE. 

The use of chains is not permitted since the EU-RDE trip speed 
requirements cannot be fulfilled and it is not recommended to 
drive on snow during EU-RDE tests and it is not recommended 
to drive under extreme weather conditions during EU-RDE tests. 

18 

 
 
 
5.2

  Selection of test routes for EU-RDE testing 

Any  trip  planner  may  be  used  to  define  a  route  which  is  likely  to  result  as  compliant 
according 
the  required 
urban/rural/motorway distance shares, the altitude difference between the start and end 
point and the cumulative altitude gain. 

in  particular  with 

trip  requirements, 

the  EU-RDE 

to 

For EU-RDE-TA and EU-RDE-ISC tests: 

•  The  trip  shall  always  start  with  the  urban  part  which  should  be  driven  on  urban 
roads  with  a  speed  limit  of  60  km/h  or  less.  In  case  the  urban  part  of  the  trip 
needs  to  be  driven  for  a  limited  period  of  time  on  roads  with  speed  limit  higher 
than  60  km/h,  the  vehicle  shall  be  driven  with  speeds  up  to  60  km/h.  The  trip 
must start with the urban driving followed by the rural and the motorway; 

•  The trip must be driven in urban-rural-motorway order, however, rural operation 
may  be  interrupted  by  urban  operation,  and  motorway  operation  can  be 
interrupted by urban and/or rural operation; 
•  The trip may start and end at the same point; 
•  The vehicle's velocity shall be above 100 km/h for at least 5 minutes; 
•  For  M2  and  N2  category  vehicles  that  are  equipped  in  accordance  with  Directive 
92/6/EEC  with  a  device  limiting  vehicle  speed  to  100  km/h  and  90  km/h,  the 
speed range of the motorway driving be above 90 km/h and 80 km/h for at least 
5 minutes, respectively. 

Once the trip or trips are defined, it is recommended to "try" them, using a data logger 
to record the vehicle speed and altitude. It is recommended to conduct such trials during 
the  times  of  the  day  which  are  intended  for  the  complete  EU-RDE  test  with  the  PEMS. 
Depending  on  the  local  traffic  situation  and  potential  traffic  jams,  it  is  also  advisable  to 
design alternative routes and/or local detours. It is also recommended to avoid using the 
same street more than twice in a specific route. 

It  is  suggested  not  to  always  select  the  same  route  for  each  EU-RDE  test,  but  to  vary 
them. It is also recommended to perform the hot EU-RDE test on the exact same route 
as equivalent cold ones. 

5.3

  Recommendations to drivers 

The drivers shall be instructed and trained according to the health, work safety, and road 
safety regulations in force locally. Local speed limits remain in force during a PEMS test, 
notwithstanding  other  legal  consequences.  Note  however,  that  violations  of  local  speed 
limits per se may not invalidate the results of test. 

For EU-RDE-TA and EU-RDE-ISC tests: 

•  The  driver  shall  be  informed  about  the  trip  composition  requirements,  stop 
requirements,  and  the  recommendations  regarding  the  vehicle  systems  (i.e.  air 
conditioning,  use  of  auxiliaries).  Drivers  shall  be  acquainted  with  the  fact  that 
temporarily  exceed  the  speed  boundaries  (60  and  90  km/h)  of  EU-RDE 
urban/rural/motorway  phases  is  allowed  as  long  as  it  does  not  compromise  the 
distance  and  shares  requirements.  For  instance,  attention  shall  be  paid  to  the 
section  intended  for  rural  driving  where  the  vehicle  speed  should  not  exceed  90 
km/h,  otherwise  risking  decreasing  the  rural  driving  share  to  the  benefit  of  the 
motorway driving and eventually making the trip invalid. 

•  The driver should be aware that the vehicle stop (vehicle speed < 1 km/h) during 
the entire cold start period shall be kept to the minimum possible and it shall not 
exceed  90  s.  In  addition,  for  conventional  vehicles  or  for  OVC-HEVs,  and  NOVC-
HEVs  starting  the  test  with  the  internal  combustion  engine  on,  the  idling 
immediately after test start shall be kept to the minimum possible and it shall not 
exceed 15 s. Ensuring a proper GNSS connection shall therefore be done prior to 
the first engine start to fulfil the 2 criteria cited above. 

19 

•  Any  biased  driving  should  be  avoided,  such  as  repeatedly  pumping  with  the 
accelerator pedal, even if it would be needed in order to keep within some of the 
boundaries. 

•  For  manual  transmission  vehicles,  it  is  recommended  that  the  driver  follows  as 
much as possible the gear shift indicator (GSI). The advice is to be no more than 
1 gear up or down from the GSI. 

•  The driver must know that if the engine stalls during the test, it may be restarted, 
but  the  sampling  shall  not  be  interrupted.  Repeated  stalling  of  the  engine 
(suddenly turned off) should be avoided during an EU-RDE trip. 

•  The driver should circulate on the road in a way which corresponds to the normal 
traffic situation. The use  of RDE-driver aid software is allowed as long as it does 
not  interfere  with  safety  (only  verbal  instructions  are  allowed  to  prevent 
distractions  to  the  driver).  The  use  of  RDE-driver  aid  software  or  verbal 
instructions during the trip shall not be used to bias the emission result or to trim 
tests towards to the limits of the valid range. For non-EU-RDE  PEMS testing, the 
same  safety  recommendations  apply.  However,  the  use  of  driver-aid  software  is 
left  to  the  discretion  of  the  tester  and  it  is  recommended  to  log  the  driving 
attitude of the driver (defensive/following traffic/aggressive). 

20 

 
 
6  Test Protocol [How to conduct the test?] 

This  section  presents  a  comprehensive  overview  of  the  emissions  testing  protocol  with 
PEMS  on  passenger  cars  and  light-commercial  vehicles.  The  aim  is  to  provide  guidance 
through  the  whole  PEMS  testing  process  including  safety  tips  on  the  installation  and 
usage  of  the  equipment.  The  step  by  step  description  is  the  result  of  the  experience  of 
PEMS  testing  at  various  European  testing  laboratories,  including  the  Joint  Research 
Centre. 

The test protocol may be adapted on a case-by-case situation depending on the vehicle 
to be tested, the available PEMS instruments, and the type of test. For RDE-TA tests, the 
Type  Approval  Authority  may  verify  if  the  test  setup  and  the  equipment  used  fulfils  the 
requirements  of  Appendices  1  and  2,  through  a  direct  inspection  or  an  analysis  of  the 
supporting  evidence  (e.g.  photographs,  records).  In  general,  it  is  a  good  practice  to 
document the installation of the instruments with pictures for traceability matters.  

6.1

  Checks  before  the  installation  of  the  instruments  in  the 

vehicle 

This  section  presents  an  overview  of  the  elements  that  shall  be  verified  on  a  vehicle 
before  proceeding  to  the  installation  of  the  measurement  equipment.  Checking  the 
elements listed in Table 8 is a way for the testing party to find out whether a test can be 
performed  according  to  the  EU-RDE  regulation  or  not  even  before  proceeding  with  the 
PEMS installation. The complete list of elements to be checked and report for EU-RDE ISC 
tests can be checked in the Annex of this guidance document. 

Table 8. Elements to be checked before the installation of the instruments 

Element 

Description/Unit 

Tyre pressure 

According to the vehicle manufacturer's recommendations 

Tyre tread depth 

OBD check 

According  to  the vehicle  manufacturer's recommendations (at  least 
3mm of tread depth for summer tyres and 4 mm for winter tyres) 

EU-RDE-TA & EU-RDE-ISC: the vehicle is not eligible in case faulty 
checks (Table 5). Print error log 

Are there any warning light activated on 
the instrument panel? 

EU-RDE-TA  &  EU-RDE-ISC:  any  Malfunction  Indication  Light  (MIL) 
makes the vehicle not eligible 

Vehicle fluids 

Check that the fluid levels (engine oil, cooling liquid, etc.) are within 
the min/max recommendations and top up if needed. 

Aerodynamic modifications 

EU-RDE-TA & EU-RDE-ISC: Verify no aftermarket aerodynamics 
modification was made (roof boxes, load racking, spoilers, etc.) and 
no standard aerodynamics components are missing (front 
deflectors, diffusers, splitters, etc.). Otherwise the vehicle is not 
eligible for testing. 

Mileage 

EU-RDE-TA: 3 000 – 15 000 

EU-RDE-ISC: 15 000 – 100 000 km 

Vehicle age 

EU-RDE-ISC: 6 months – 5 years 

Country of registration and use 

EU-RDE-TA  &  EU-RDE-ISC:  EU  country,  registered  and  used  in  the 
European Union for at least 90% of the time 

Is the vehicle involved in a recall or 
service campaign? 

EU-RDE-ISC: vehicle not eligible if the repair was not done 

21 

 
 
Elements to be checked before the installation of the instruments (continued) 

Element 

Description/Unit 

Was the vehicle used for racing/motor 
sport? 

EU-RDE-ISC: if yes, vehicle not eligible 

Has the vehicle carried heavy loads over 
the specifications of the manufacturer? 

EU-RDE-ISC: if yes, vehicle not eligible 

Check for traces of tuning 

EU-RDE-ISC: if yes, vehicle not eligible 

Was any part of the emissions after-
treatment system replaced  

EU-RDE-ISC:  if  not original  parts  were  used  as  replacement,  the 
vehicle is not eligible 

Service and repair history 

EU-RDE-ISC: if the full documentation supporting that the vehicle 
has  been  maintained  according 
the  manufacturer's 
recommendations cannot be provided, the vehicle is not eligible 

to 

6.2

  Installation of instruments (Detailed by PEMS component) 

STEP 1. 

Installation of the PEMS main unit 

The main PEMS main shall be installed according to the specifications of the instruments 
supplier,  in  such  a  way  that  it  minimises  electromagnetic  interferences,  exposition  to 
dust, shocks, vibrations and excessive heating (Figure 3). In addition, the installation and 
operation  of  the  PEMS  shall  be  leak-tight  and  minimise  heat  losses.  Access  to  the  test 
equipment shall not be prevented – in view of the potential checks during or between the 
tests.  After  the  installation  of  PEMS  is  completed,  a  leak  check  shall  be  performed  at 
least once for each PEMS-vehicle installation as prescribed by the PEMS manufacturer or 
as  follows.  The  probe  shall  be  disconnected  from  the  exhaust  system  and  the  end 
plugged. The analyser  pump shall be switched on. After an initial stabilisation period all 
flow  meters  shall  read  approximately  zero  in  the  absence  of  a  leak.  Else,  the  sampling 
lines shall be checked and the fault corrected. 

  The  main  unit  should  be  secured  with  load  straps  or  according  to  the  instrument 

supplier recommendations (Figure 3). 

 When the unit is installed inside the vehicle, the PEMS unit should be equipped with 

gas monitors or warning systems for hazardous gases (e.g. CO). 

  The  mounting  location  should  be  chosen  so  that  the  unit's  cooling  fans  are 
unobstructed.  Sample  stream  exhaust  lines  should  be  routed  outside  of  the  vehicle's 
cabin  in  order  to  prevent  contamination  of  the  vehicle  cabin  environment.  These  lines 
should  be  routed  in  such  a  manner  as  to  prevent  pinching  or  rupturing  and  should  be 
without strains in order to prevent damage due to vibrations. 

 PN analyser, especially those with working fluids should be installed horizontally. 

  Warnings  of  the  vehicle  or  PEMS  before,  during  or  after  the  test  shall  be 
documented  and  actions  taken  according  to  the  vehicle  -or  instrument-manufacturer’s 
recommendations. 

22 

 
 
Figure 3. 
left) installation of PEMS main units outside the vehicle;  
centre) installation outside on small cars without hook;  
right) securing the instruments with straps inside the vehicle 

Source: left) HORIBA; centre) MAHA-AIP GmbH & Co.; right) JRC VELA lab 

STEP 2.  Selection of the exhaust flow meter range 

For EU-RDE-TA, the exhaust mass flow has to be measured by means of an Exhaust Flow 
Meter  (EFM).  It  is  recommended  to  select  the  EFM  in  order  to  have  the  maximum 
expected flow  rate during the test covering at least 75%  of the  EFM  full range. For  EU-
RDE  ISC  tests,  the  exhaust  flow  can  be  calculated  (using  ECU  signals  or  appropriate 
sensors)  or  measured  by  means  of  an  EFM.  In  the  latter  case,  the  selection  of  the  EFM 
shall follow the same recommendations as for EU-RDE-TA tests. 

STEP 3. 

Installation of the exhaust flow meter 

Whenever  used,  the  exhaust  mass  flow  meter  shall  be  attached  to  the  vehicle's 
tailpipe(s)  in  accordance  with  the  recommendations  and  calibration  of  the  EFM 
manufacturer.  The  EFM  shall  not  change  the  nature  of  the  exhaust  gas  nor  unduly 
increase  the  length  of  the  tailpipe  or  increase  the  pressure  at  the  exhaust  outlet.  It  is 
advisable  that  the  additional  backpressure  does  not  exceed  20  mbar.  Any  bend  in  the 
exhaust  pipe  should  be  smooth  and  of  sufficient  radius  (sharp  90-degree  bends  can 
affect  the  exhaust  flow  readings).  The  installation  of  the  EFM  and  any  exhaust  pipe 
adaptors  or  junctions  shall  not  adversely  affect  the  operation  of  the  engine  or  exhaust 
after-  treatment  system.  A  small  downwards  inclination  is  recommended  to  reduce  any 
condensation  sink  in  the  EFM.  The  EFM  shall  be  purged  and  prepared  for  operation  in 
accordance  with  the  specifications  of  the  EFM  manufacturer.  This  procedure  shall,  if 
applicable,  remove  condensation  and  deposits  from  the  lines  and  the  associated 
measurement  ports.  When  testing  a  multi-cylinder  engine  with  a  branched  exhaust 
manifold,  it  is  recommended  to  position  the  exhaust  mass  flow  meter  downstream  of 
where the manifolds combine and to increase  the cross  section of the piping such as to 
have  an  equivalent,  or  larger,  cross  sectional  area  from  which  to  sample.  If  this  is  not 
feasible,  exhaust  flow  measurements  with  several  exhaust  mass  flow  meters  may  be 
used. The wide variety of exhaust pipe configurations, dimensions and exhaust mass flow 
rates may require compromises, guided by good engineering judgement, when selecting 
and installing the EFM(s). It is permissible to install an EFM with a diameter smaller than 
that of the exhaust outlet or the total cross-sectional area of multiple outlets, providing it 
improves  measurement  accuracy  and  does  not  adversely  affect  the  operation  or  the 
exhaust after-treatment as specified in point 3.4.2. The accuracy of the EFM, defined as 
the  deviation  of  the  EFM  reading  from  the  reference  flow  value,  shall  not  exceed  ±  3 
percent  of  the  reading,  0,5  %  of  full  scale  or  ±  1,0  per  cent  of  the  maximum  flow  at 
which the EFM has been calibrated, whichever is larger. 

The installation of the EFM shall be documented using photographs. 

23 

 
  To  avoid  damage  to  the  engine  or  negatively  affect  exhaust-after-treatment 
systems  a  minimum  of  four  pipe  diameters  or  150  mm  of  straight  tubing,  whichever  is 
larger,  shall  be  placed  at  either  side  of  the  flow-sensing  element.  In  addition,  abrupt 
changes of diameters shall be avoided. 

For  the  installation  of  the  EFM,  different  solutions  are  available,  depending  on  exhaust 
configuration and expected exhaust temperatures. 

•  Solution 1 (recommended): Clamping and fixation point 

The first solution is to weld two identical flanges on the tailpipe and on one end of 
the  EFM.  These  two  flanges  should  then  be  clamped  whereas  a  sealing  material 
must  be  used  to  minimise  exhaust  leakage  (Figure  4).  This  solution  is  safe, 
makes  easy  the  installation  and  possible  re-installation  of  the  EFM  and  also 
eliminates  the  risk  to  see  the  alignment  of  the  Pitot  tubes  modified  because  of 
vibrations. 

Figure 4. Installation of the EFM: elements for clamping 

Source: ACEA 

•  Solution  2  (to  be  used  if  solution  1  cannot  be  achieved  with  reasonable  effort.): 

Specific tailpipe adapters (Figure 5) 

 A fixation point is always needed to secure the EFM (Figure 5). 

  To  prevent  heating  and  possible  damages,  the  outlet  of  the  EFM  should  not  be 

directed towards a tyre or other vehicle components. 

24 

 
  In  case  silicon  tubes  (secured  with  collars)  are  used  to  attach  the  EFM  to  the 
vehicle's tailpipe, the silicon must never be directly in contact with the exhaust gas since 
new  silicon  ducting  in  contact  with  the  exhaust  gas  at  high  temperature  may  generate 
large amounts of particles. 

Remarks: 

•  The clamps and the mounting of the EFM should be visually inspected before the 
initial  test  and  between  each  subsequent  test.  It  is  recommended  to  secure 
clamps by appropriate measures (cable strips or splint pins). 

•  The Pitot sensor should be placed between two pieces of straight tube of the same 
diameter  whose  length  should  be  at  least  4  times  the  Pitot  diameter  (upstream 
and downstream). 

•  The  EFM  shall  be  placed  after  the  vehicle  silencer  (if  any),  to  limit  the  effect  of 

exhaust gas pulsations upon the measurements. 

•  •All electronics (PEMS and EFM) shall be mounted in such a way that the cooling 
air-flow  is  sufficient  but  they  are  not  exposed  to  too  excessive  conditions  (rain, 
splash water). 

•  The  PN  and  gas  sampling  should  be  done  from  the  centerline  of  the  EFM.  If 
particles  are  sampled,  then  the  probe  should  be  placed  upstream  of  the  other 
sampling probes (for gases). 
It  shall  be  ensured  that  the  sampling  system  is  clean  and  free  of  moisture 
condensation. 

• 

•  The  EFM,  once  mounted  should  not  prevent  the  access  to  important  vehicle 
functions such as the spare wheel, fuses, etc. since those may be needed on the 
road.  In  case  a  tyre  or  a  fuse  has  to  be  changed  during  an  official  EU-RDE  test 
that test should be voided. 

•  For  dual  exhaust  configurations,  it  is  recommended  that  Y-connection  shall  be 
implemented  so  that  the  entire  exhaust  stream  is  sampled  by  the  exhaust  flow 
meter test section.  

•  The thermocouple to measure the exhaust temperature is part of the EFM. 
•  According  to  instrument  manufacturers'  specifications,  EFM  can  stand  exhaust 
temperatures of at least 600°C in continuous operation if cooling of electronics is 
adequate. 

•  For  EU-RDE-TA  it  is  necessary  to  document  the  EFM  set-up  using  photographs 

(Figure 6). 

Figure 5. EFM Installation 
left) using a tailpipe adaptor; 
right) tubes and collars on a dual exhaust 

Source: JRC VELA lab 

25 

 
 
 
Figure 6. 
left) examples of EFM installation when the PEMS main unit is installed inside the vehicle; 
right) proper signalling of the EFM 

Source: JRC VELA lab 

STEP 4.  Mounting of the GNSS antenna 

The  antenna  should  be  mounted  at  the  highest  possible  location,  without  risking 
interference  with  any  obstructions  encountered  during  on-road  operation.  Mounting  is 
accomplished with either a magnetic or fixed mount post (Figure 7). 

Figure 7. Installation examples for the GNSS antenna and the weather station 

Source: JRC VELA lab 

STEP 5.  Preparation of the ECU communication cables 

If desired for non-EU-RDE types of PEMS testing, relevant vehicle and engine parameters 
listed in Table 2 can be recorded by using a data logger connected with the ECU or the 
vehicle network through standards, such as ISO 15031-5 or SAE J1979, OBD-II, EOBD or 
WWH-OBD.  If  ECU  parameters  are  obtained,  these  may  be  obtained  at  a  substantially 
higher frequency but the recording rate shall be 1.0 Hz. When applicable, manufacturers 
shall disclose the labels which allow the correct identification of available parameters. 

STEP 6.  Connection and installation of the ECU communication cable 

The cable shall be routed in such a manner as to provide minimum interference to vehicle 
occupants.  The  ECU  communication  cable  shall  be  shorter  than  5  meters  in  order  to 
minimize the effect of radio waves to the measurements. In addition, the unit should be 
securely  mounted  in  the  cab  of  the  test  vehicle  in  a  location  that  does  not  permit 
unnecessary moisture, vibration, or excessive operating temperatures (Figure 8). 

26 

 
 
Figure 8. 
left) connection to the vehicle ECU; 
right) secure mounting of a laptop connected to the OBD reader. 

Source: JRC VELA lab 

STEP 7. 

Installation of the power supply 

In  order  to  accommodate  the  power  requirements  of  a  complete  PEMS  system,  it  is 
recommended to use a set of rechargeable batteries (AGM, gel, or lithium-ion) as light as 
possible. 

The batteries shall be safely installed and secured on the vehicle or in the PEMS. The 

use of straps to securely attach them to the vehicle is essential (Figure 9). 

Figure 9.left) Charging of the batteries;  
centre) batteries to operate the PEMS, located in the trunk, properly secured with straps; 
right) example of PEMS main unit with portable batteries. 

Source: left) JRC VELA lab; centre) Sensors, Inc.; right) MAHA-AIP GmbH & Co. 

Remark:  When  measuring  THC  emissions  with  PEMS,  the  heated  probe  and  the  heated 
FID  are  responsible  for  a  significant  part  of  the  power  consumption.  For  some 
configurations,  cold  ambient  temperatures  and  highway  driving  conditions  (forced 
cooling)  may  significantly  affect  the  behaviour  of  the  heated  probe  and  its  temperature 
control. 

STEP 8. 

Installation of the weather station 

Install  the  weather  station  on  the  outside  of  the  cab  in  a  location  that  is  shielded  from 
direct  air-flow  and  contamination  from  debris.  The  temperature  sensor  should  be 
shielded  from  any  warm-up  effects  like  hot  air  coming  from  the  vehicle  engine  or 
exhaust.  The  mounting  location  of  the  ambient  absolute  pressure  transducer  shall  be 
selected such that air motion effects on the sensor are minimised (Figure 7). 

27 

 
 
STEP 9.  Connection of the heated probe(s) 

Connect the inlet of the heated sampling line to the sampling probe port located on the 
exhaust flow rate measurement tube. Connect the  outlet of the heated sampling line to 
the  inlet  port  on  the  PEMS  exhaust  sample  conditioning  unit.  If  particles  are  measured, 
the  exhaust  shall  be  sampled  from  the  centre  of  the  exhaust  stream.  If  several  probes 
are used for emissions sampling, the particle sampling probe should be placed upstream 
of  the  other  sampling  probes.  The  particle  sampling  probe  should  not interfere  with  the 
sampling of gaseous pollutants. 

Any replacement involving a modification of the length of the heated probe must be done 
in consultation with the instrument manufacturer, as it directly alters the time-alignment 
within the PEMS. If the PEMS main unit is installed in the trunk, it is recommended that 
the  sampling  line  be  routed  through  side  windows  or  access  doors  (Figure  10).  When 
installed  outside,  the  heated  probe  shall  be  routed  in  a  way  to  secure  visibility  for  the 
driver and minimise aerodynamic resistance (Figure 10). 

Make  sure  that  the  heated  probe  is  properly  insulated,  especially  at  the  connection 
points:  EFM  and  back  of  the  analysers,  to  avoid  cold  spots  potentially  causing  errors  in 
emissions measurements (e.g. condensation and evaporation of gases). 

Figure 10. Routing heated probe 
left) from the inside of the vehicle; 
right) outside of the vehicle. 

Source: left) JRC VELA lab; right) AVL LIST GmbH  

STEP 10.  Connection of other tubes and cables 

Connect  the  different  cables  and  tubes  as  described  in  the  manuals  of  the  instruments. 
Avoid  sharp  bends,  loose  cable  loops  or  dangling  parts.  They  could  get  damage  during 
testing. No parts, cables or tubes shall touch the ground or moving parts of the vehicle. 

 The wiring should be routed in such a manner as to prevent pinching and should be 
free  of  strains  in  order  to  prevent  damage  due  to  vibrations  and  relative  movement 
between vehicle chassis/body components. 

28 

 
 
 
6.3

  Pre-Test Procedures 

STEP 11.  Check connections and wirings 

To be made every > Single Test 

  Prior  to  supplying  power  to  the  instruments,  visually  inspect  all  connections  to 
check  if  they  are  loose,  possibly  due  to  vibrations.  Safety  rules  should  be  followed,  in 
particular because there can be electrical power even with switched-off equipment. 

STEP 12.  Verify the PEMS power supply batteries charge level 

To be made every > Single Test 

The  batteries  shall  be  charged  prior  the  PEMS  test.  It  is  recommended  to  perform  the 
pre-test with the batteries connected to the power supply to prevent its depletion before 
the actual test. 

STEP 13.  Power-up the main software 

To be made every > Single Test 

It  is  recommended  to  follow  the  PEMS  manufacturer  initialisation  procedure  of  the 
software to guarantee the operability of all the instruments. All available signals shall be 
checked for consistency, in particular, the main software may warn of incorrect electrical 
connections/cable breaks. The PEMS shall function free of errors and critical warnings. 

STEP 14.  Starting and stabilizing the main unit 

To be made every > Day (Better is to keep equipment in stand-by once installed) 

The  PEMS  shall  be  switched  on,  warmed  up  and  stabilised  in  accordance  with  the 
specifications of the PEMS manufacturer until key functional parameters, e.g., pressures, 
temperatures  and  flows  have  reached  their  operating  set  points  before  test  start.  To 
ensure correct functioning, the PEMS may be kept switched on or can be warmed up and 
stabilised  during  vehicle  conditioning.  The  system  shall  be  free  of  errors  and  critical 
warnings. 

If  possible  the  warming  up  mode,  pause  mode  and  standby  mode  of  the  instrument 
should be powered from the power socket while keeping the instrument battery charged. 

The  sampling  system,  consisting  of  the  sampling  probe  and  sampling  lines  shall  be 
prepared  for  testing  by  following  the  instruction  of  the  PEMS  manufacturer.  It  shall  be 
ensured  that  the  sampling  system  is  clean  and  free  of  moisture  condensation.  If 
hydrocarbons are measured, the sampling line shall be heated to 464 ± 10 K (191 ± 10 
°C).  For  the  measurement  of  other  gaseous  components  with  or  without  cooler,  the 
sampling line shall be kept at a minimum of 333 K (60 °C) to avoid condensation and to 
ensure appropriate penetration efficiencies of the various gases. If particles are sampled 
and  not  diluted  at  the  tailpipe,  the  sampling  line  from  the  raw  exhaust  sample  point  to 
the point of dilution or particle detector shall be heated to a minimum of 373 K (100 °C). 
The residence time of the sample in the particle sampling line shall be less than 3 s until 
reaching first dilution or the particle detector. 

For EU-RDE-TA and EU-RDE-ISC tests the ambient temperature sensor shall be checked 
to  verify  if  the  ambient  temperature  boundary  conditions  are  fulfilled.  This  is  also 
recommended for other types of tests. 

29 

 
 
STEP 15.  Check of zero level of the analysers 

To be made every > Single Test 

Zero  verifications  of  the  analysers  shall  be  performed  using  gases  which  fulfil  the 
specifications  of  Regulation  2017/1151  Appendix  2,  point  5.  The  shelf  life  of  calibration 
and  span  gases  shall  be  respected.  The  zero  response  drift,  defined  as  the  mean 
response to zero  flow during a time interval of at least 30  seconds, has to be less than 
±2  per  cent  of  the  maximum  value  of  the  primary  signal  recorded  at  the  flow  at  which 
the EFM was  calibrated over a period of 4 hours (pre-test vs post-test are  compared to 
calculate  zero  level  drift).  The  zero  response  drift  must  be  within  the  permissible 
response defined in point 6 Appendix 1 (Table 2) of RDE Regulation. 

For  EU-RDE-TA  and  EU-RDE-ISC  tests,  it  is  required  that  the  zero  level  of  the  particles 
analyser  shall  be  recorded  by  sampling  HEPA  filtered  ambient  air  at  an  appropriate 
sampling point, usually at the inlet of the sampling line. The signal shall be recorded at a 
constant  frequency  which  is  a  multiple  of  1.0  Hz  averaged  over  a  period  of  2  minutes; 
the  final  concentration  shall  be  within  the  manufacturer’s  specifications,  but  shall  not 
exceed 5 000 particles per cubic-centimetre. 

For  non  EU-RDE  tests,  when  ambient  air  is  used  to  zero  the  analysers,  make  sure  that 
the  air  is  not  sampled  near  a  contamination  source  (e.g.  other  engine).  Preferably  use 
HEPA filtered air. 

STEP 16.  Span calibration of the analysers 

To be made every > Single Test 

The calibration gases shall cover at least 90% of the concentration values obtained from 
99 % of the measurement of the valid parts of the emissions test. It is permissible that 1 
% of the total number of measurements used for evaluation exceeds the used span gas 
by up to a factor of two. If these requirements are not met, the test shall be voided. For 
the first test, the calibration span of the emissions analysers shall be performed using the 
span-gas  concentrations  recommended  by  the  instruments  manufacturer.  To  minimize 
analyser  drift,  one  should  conduct  the  zero  and  span  calibration  of  analysers  at  an 
ambient  temperature  that  resembles,  as  closely  as  possible,  the  temperature 
experienced by the test equipment during the trip. 

For EU-RDE tests, the gases shall fulfil the requirements laid down in EU-RDE Regulation, 
Appendix  2.  In  particular,  the  span  response  drift,  defined  as  the  mean  response  to  a 
span flow during a time interval of at least 30 seconds, shall be less than ± 2 per cent of 
the  maximum  value  of  the  primary  signal  recorded  at  the  flow  at  which  the  EFM  was 
calibrated over a period of 4 hours (pre-test vs post-test are compared to calculate zero 
level  drift).  The  span  response  drift  must  be  within  the  permissible  response  defined  in 
point  6  Appendix  1  (Table  2)  of  the  EU-RDE  Regulation.  PN  span  drift  check  is  not 
currently  feasible.  Pure  as  well  as  mixed  calibration  and  span  gases  shall  fulfil  the 
specifications of Regulation 2017/1151. 

NO2  calibration  gas is  permissible.  The  concentration  of  the  NO2  calibration  gas  shall  be 
within two per cent of the declared concentration value. The amount of NO contained in 
the NO2 calibration gas shall not exceed 5 per cent of the NO2 content. 

STEP 17.  Archiving zero level and span calibration data 

To be made every > Single Test 

 Zero and span verification records must be archived, including the results before and 

after the PEMS testing, and the details of the gases used. 

30 

 
 
STEP 18.  Exhaust flow meter cleaning 

To be made every > Single Test 

For  EU-RDE  tests,  when  the  EFM  is  used  to  measure  the  exhaust  mass  flow,  it  shall  be 
purged  and  prepared  for  operation  in  accordance  with  the  specifications  of  the  EFM 
manufacturer. This procedure shall, if applicable, remove condensation and deposits from 
the lines and the associated measurement ports. 

STEP 19.  Gas analyser System Leak Check 

To be made every > Every new PEMS installation 

This  procedure  should be  conducted  according  to  the  recommendations  provided  by  the 
instrument  manufacturer  or  as  follows  (Text  from  EU-RDE  Regulation,  Appendix  1, 
Section 4.1). 

The  probe  shall  be  disconnected  from  the  exhaust  system  and  the  end  plugged.  The 
analyser  pump  shall  be  switched  on.  After  an  initial  stabilization  period  all  flow  meters 
shall read approximately zero in the absence of a leak. Else, the sampling lines shall be 
checked  and  the  fault  corrected.  The  leakage  rate  on  the  vacuum  side  shall  not  exceed 
0.5  per  cent  of  the  in-use  flow  rate  for  the  portion  of  the  system  being  checked.  The 
analyser flows and bypass flows may be used to estimate the in-use flow rates. 

Alternatively, the system may be evacuated to a pressure of at least 20 kPa vacuum (80 
kPa  absolute).  After  an  initial  stabilization  period  the  pressure  increase  ∆p  (kPa/min)  in 
the system shall not exceed: 

 CPC based PN-analysers can be severely damaged by vacuum.  

Alternatively, a concentration step change at the beginning of the sampling line shall be 
introduced  by  switching  from  zero  to  span  gas  while  maintaining  the  same  pressure 
conditions as under normal system operation. If  for a correctly calibrated analyser after 
an  adequate  period  of  time  the  reading  is  ≤99  per  cent  compared  to  the  introduced 
concentration, the leakage problem shall be corrected. 

STEP 20.  Verification of the flow meter 

To be made every > Single Test 

Before every PEMS test, the EFM has to be verified in accordance with the specifications 
of  the  EFM  manufacturer.  It  is  recommended  to  visually  check  the  EFM  zero  flow  and 
verify it from the  PEMS data logged before the combustion engine starts. Only the zero 
value can be validated. 

STEP 21.  Check that  data  acquisition storage media and backup  have  sufficient 

space 

To be made every > Single Test 

The memory of the system shall allow sufficient storage capacity for at least 120 minutes 
test. 

STEP 22.  Spot check 

To be made every > Single Test 

Log  onto  the  data  acquisition  computer  and  start  the  PEMS  data  acquisition  program. 
Verify that all pertinent data is being recorded (spot check). Sampling, measurement and 

31 

 
recording of parameters shall begin prior to the test start. Before the test start it shall be 
confirmed that all necessary parameters are recorded by the data logger. 

To facilitate time alignment, it is recommended to record the parameters that are subject 
to  time  alignment  either  by  a  single  data  recording  device  or  with  a  synchronised  time 
stamp.  

STEP 23.  Check GNSS 

To be made every > Single Test 

Check GNSS signals and GNSS status. 

The GNSS signal shall be logged from the first sec.  

Care  has  to  be  taken  to  avoid  prolonged  idling  of  the  vehicle  while  waiting  for  GNSS 
signal  since  this  may  void  the  test  for  exceeding  the  maximum  stop  time  from  EU-RDE 
requirements. 

STEP 24.  Check weather station 

To be made every > Single Test 

Check that ambient temperature, humidity, and pressure are properly registering and the 
monitored values are displayed in the data acquisition computer. 

STEP 25.  Verify that all temperature controllers are set at the correct operating 

values 

To be made every > Single Test 

When the vehicle is soaked inside it is important to check during the first minutes of the 
test that the temperature measured by the weather station gets properly aligned to the 
ambient temperature provided by the vehicle. 

STEP 26.  Switch to batteries power 

This  can  be  done  shortly  before  the  test  starts.  Otherwise,  standard  230V  electrical 
power should be used from a building, in particular to warm up the instruments. 

STEP 27.  Start the engine 

To be made every > Single Test 

Start the engine for cold-start test. For warm engine condition tests it is possible to drive 
a  hot  test  just  after  a  cold  one.  However,  since  the  test  end  is  defined  as  "when  the 
vehicle  has  completed  the  trip  and  the  combustion  engine  is  switched  off"  (Point  5.3  of 
Appendix 1), it is not possible to keep the engine on in between PEMS tests. In between 
PEMS tests, the PEMS shall be reconnected to the power supply of the building. 

STEP 28.  When applicable, Check ECU communication 

To be made every > Every new PEMS installation 

When applicable, check that the system is correctly displaying and recording ECU data. 

32 

 
 
6.4

  Test runs 

Pre-test including validation test (Recommended) 

To be made every > Every new PEMS installation 

 To check the correct installation and functioning of the PEMS instruments before an 
on-road test, the test vehicle may be operated during a few minutes. All the data shall be 
recorded during this procedure and checked. 

For EU-RDE-TA and EU-RDE-ISC tests, it is highly recommended to conduct a validation 
test  according  to  Appendix  3  of  the  EU-RDE  Regulation,  preferably  before  the  actual 
PEMS test. Such a test will evaluate the correct installation and functionality of the PEMS 
and  the  correctness  of  exhaust  mass  flow  rate  measurements  as  obtained  from  one  or 
multiple  non-traceable  exhaust  mass  flow  meters  or  as  calculated  from  sensors  or  ECU 
signals  under  laboratory  conditions.  For  the  validation  of  the  PEMS  installation  it  is 
recommended  to  follow  the  best  practices  contained  in  the  Joint  Research  Centre 
guidance note1. 

As a pre-test inspection, the exhaust flow rate measurement pressure transducers signal 
and  emissions  measurement  system  integrity  shall  be  verified  by  acquiring  data  for  30 
seconds  with  the  vehicle  engine  idling  in  warm  engine  conditions.  This  data  should  be 
examined  for  any  anomalies,  and  corrective  measures  should  be  initiated  if  any  were 
identified. 

  Note  that  the  validation  test  should  be  considered  as  a  separate  test  (and  hence 
have  its  own  zero  and  span  calibrations  before  and  after  the  test).  Such  tests  must  be 
exercised with care: Installation of EFMs (equipped with sensitive pressure transducers), 
the selection and the design of the sampling points are of great importance and shall be 
conducted using the best available engineering practice. 

Once  verified  and  correctly  set  in  the  PEMS,  the  time  alignment  settings  shall  not  be 
changed during the following tests. 

Verification of pre-test or validation test data 

To be made every > Every new PEMS installation 

The following data screening is recommended: 

•  Analysers  concentrations:  check  for  the  measured  ranges,  eventual  range 

saturation and anomalous values; 

•  Vehicle ground speed, comparing the values from the ECU (when applicable) and 

from the GNSS (when applicable); 

•  Exhaust  mass  flow,  comparing  the  direct  measurement  of  the  EFM  to  a  'backup' 
value (e.g. the  exhaust mass flow  recalculated from  ECU  fuel mass flow and A/F 
ratio); 

•  Comparing  integral  values  of  different  phases  of  total  of  an  appropriate  driving 

cycle and a CVS. 

•  Ambient  conditions,  comparing  the  values  from  the  weather  station  to  the  ones 

given by specific sensors. 

STEP 29.  Normal test run 

Sampling,  measurement  and  recording  of  parameters  shall  begin  prior  to  the  test  start 
(Figure 11). For EU-RDE, the test start shall be defined by either: 

• 

the first ignition of the internal combustion engine; 

1 Recommendations for the validation of PEMS in the laboratory (under development). 

33 

                                           
•  or  the  first  movement  of  the  vehicle  with  speed  greater  than  1  km/h  for  OVC-

HEVs and NOVC-HEVS starting with the internal combustion engine off. 

For non-EU-RDE tests, it is recommended to use the same definition for the test start. 

Figure 11. Test start sequence. 

Source: EU-RDE LDV regulations 

Sampling,  measurement  and  recording  of  parameters  shall  continue  throughout  the  on-
road test of the vehicle. The engine may be stopped and started, but emissions sampling 
and  parameter  recording  shall  continue.  The  data  recording  shall  continue  until  the 
response  time  of  the  sampling  systems  has  elapsed.  An  OBD-check  shall  be  performed 
and documented directly after test end (Figure 12).  

6.5

  Post-test  

STEP 30.  Conclusion of a test run 

The end of the test is reached when the vehicle has completed the trip and either when: 

• 
• 

the internal combustion engine is switched off; 
for  OVC-HEVs  and  NOVC-HEVS  finishing  the  test  with  the  internal  combustion 
engine off, the vehicle stops and the speed is lower than or equal to 1 km/h. 

Figure 12. Test end sequence. 

Source: EU-RDE LDV regulations 

34 

 
 
Any  warning  signals,  suggesting  malfunctioning  of  the  PEMS  and  the  vehicle,  shall  be 
documented  and  verified.  If  any  error  signal(s)  of  the  PEMS  instrumentation  appear 
during the test, the test shall be voided. 

Parameter  recording  shall  reach  a  data  completeness  higher  than  99  %.  Measurement 
and data recording may be interrupted for less than 1 % of the total trip duration but for 
no more than a consecutive period of 30 s solely in the case of unintended signal loss or 
for  the  purpose  of  PEMS  system  maintenance  only.  Interruptions  may  be  recorded 
directly  by  the  PEMS  but  it  is  not  permissible  to  introduce  interruptions  in  the  recorded 
parameter  via  the  pre-processing,  exchange  or  post-processing  of  data.  It  is 
recommended  to  follow  the  PEMS  manufacturer  recommendations  on  how  to  deal  with 
auto-zeroing equipment. It is strongly recommended to initiate PEMS system verifications 
during periods of zero vehicle speed. 

Excessive idling of the engine after the completion of the trip shall be avoided. The data 
recording shall continue until the response time of the sampling systems has elapsed. For 
vehicles  with  a  signal  detecting  regeneration  (see  line  42  in  the  Transparency  List  1  in 
Appendix  5  of  Annex  II),  the  OBD-check  shall  be  performed  and  documented  directly 
after data recording and before any further driven distance is driven. 

STEP 31.  Zero and span check of gas analysers 

To be made every > Single Test 

  Zero  and  span  procedure  should  be  performed  on  the  emissions  measurement 

sensors/analysers according to the pre-test procedures section. 

For  EU-RDE-TA  &  EU-RDE-ISC  tests,  the  zero  and  span  check  shall  be  conducted 
according to the requirements laid down in the EU-RDE Regulation and the post-test zero 
and span data listed in Table 1 of Appendix 8 shall be recorded. 

STEP 32.  Zero of exhaust flow-meter 

To be made every > Single Test 

The values displayed by the  exhaust  flow meter shall be referenced  against pre-test 

values and recorded. 

STEP 33.  Post-test OBD check 

It is recommended to check the vehicle for OBD messages after test end to find out if the 
vehicle registered failures or malfunctions during the test as indicated in Table 5. 

STEP 34.  Back up test data 

It is recommended to perform a backup of the test data as soon as possible after the end 
of the test.  

STEP 35.  Verification of test data 

To be made every > Single Test 

The same recommendations as for the verification of the pre-test data shall apply. 

STEP 36.  Turn off the emissions sampling system and all measurement devices 

It  is  recommended  to  follow  the  shutdown  sequence  described  in  the  manufacturer's 
instructions. 

STEP 37.  Remove power from the instruments 

35 

6.6

  Conclusion of Test Series (PEMS dismounting) 

STEP 38.  Dismount  PEMS  equipment  and  restore  vehicle/machine  to  the 

original configuration 

To be made every > Every new PEMS installation 

After  a  reasonable  time  of  cooling  down,  disconnect  the  heated  sampling  line  from  the 
exhaust  sampling  port,  all  data  cables  and  transducer  lines,  remove  instruments  and 
restore the vehicle exhaust system to its pre-test configuration. 

STEP 39.  Weight of the installed PEMS equipment (including batteries) 

To be made every > Every new PEMS installation 

The total weight of the installed equipment shall be measured and recorded. 

36 

 
 
7  Data screening [How to evaluate the quality of the 

measurements?] 

7.1

  Introduction 

This  section  only  regards  the  data  screening,  i.e.  the  steps  which  must  be  taken  to 
ensure that the quality of the data is sufficient to proceed with the ex-post evaluation. 

For EU-RDE-TA and EU-RDE-ISC tests, the mandatory ex-post evaluation is comprised of 
several  steps  illustrated  in  for  steps  B  to  D,  which  address  the  trip  compliance  (Figure 
13): 

•  STEP A: To ensure that parameter recording reaches a data completeness higher 

than 99 % 

•  STEP  B:  The  trip  complies  with  the  general  requirements,  boundary  conditions, 
trip  and  operational  requirements,  and  the  specifications  for  lubricating  oil,  fuel 
and  reagents  defined  in  points  4  to  8  of  Annex  IIIa  and  Appendix  7b  of  the  EU-
RDE Regulation; 

•  STEP C: The trip complies with the requirements defined in Appendices 7a of the 

EU-RDE Regulation; 

•  STEP D: The trip complies with the requirements defined in Appendix 5 of the EU-

RDE Regulation. 

Figure 13. Verification of trip validity according to EU-RDE 

Source: EU-RDE LDV regulations 

If at least one of the requirements is not fulfilled, the trip shall be declared invalid. 

The  emissions  calculations  shall  be  made  between  test  start  (Figure  11)  and  test  end 
(Figure 12). Compliance of the software tool used to verify the trip validity and calculate 
emissions in accordance with the provisions laid down in Appendices 4, 5, 6, 7a, and 7b 
shall be validated by the tool provider or a type approval authority. Where such software 
tool  is  incorporated  in  the  PEMS  instrument,  proof  of  the  validation  shall  be  provided 
along with the instrument.  

For  other types of  PEMS testing, the  ex-post  evaluation is conducted on a case-by-case 
basis. 

37 

 
7.2

  Test data screening 

At the end of each test or a series of tests, the following items shall be checked prior to 
any data processing: 

•  Presence of mandatory parameters for EU-RDE tests (Table 2); 
•  Quality  screening  of  mandatory  parameters.  Check  for  the  measured  ranges, 
possible empty ranges of data, saturation of measurement range and/or negative 
values (Table 9). 

•  Presence  of  zero  drift  and  span  drift  results  for  THC,  CO,  NOx  (or  NO/NO2),  CO2, 

and PN. 

•  Zero drift of the exhaust flow meter. 
•  Correctness of test conditions not requiring any data processing (Table 7). 
•  Presence of regeneration events (Recommended practice in 7.3). 
•  Signal noise level, considering that noise means two times the root mean square 
of ten standard deviations, each calculated from the zero responses measured at 
a constant frequency which is a multiple of 1.0 Hz during a period of 30 seconds, 
shall not exceed 2 % of full scale. 

Should  one  of  these  items  reveal  problems  in  the  quality  of  the  data  and/or  the  non-
compliance  of  the  testing  conditions,  proceeding  to  the  ex-post  evaluation  (i.e.  the 
emissions calculations) should be avoided. 

38 

 
 
Table 9. Recommended ranges for data quality screening 

Parameter 

Recommended range for screening 

Wet CO2 [ppm] 

Wet O2 [ppm] 

Wet CO [ppm] 

Wet THC [ppm] 

Wet NOx [ppm] 

Wet NO2 [ppm] 

Wet NO [ppm] 

PN [#/m3] 

Exhaust mass flow [kg/s] 

Exhaust temperature [K] 

Relative humidity [%] 

Atmospheric pressure [kPa] 

0; 200 000 

0; 500 000 

0; 800 000 

0; 10 000 

0; 2 500 

0; 2 500 

0; 2 500 

0; 2 000 000 

0; 0.25 

0; 1 000 

0; 100 

0; 150 

Ambient temperature [K] 

250; 323 

ECU Engine Torque [Nm] 

-5 000; 5 000 

ECU Engine Speed [rpm] 

0; 10 000 

ECU Vehicle speed [km/h] 

ECU Fuel Rate [g/s] 

ECU Coolant Temperature [K] 

GNSS Latitude [degrees] 

GNSS Longitude [degrees] 

Altitude [m] 

GNSS Vehicle speed [km/h] 

0; 200 

0; 100 

0; 600 

0; 180 

-80; 80 

0; 5 000 

0; 200 

39 

 
 
7.3

  Verification of (DPF) regeneration event 

There is no systematic and absolute evidence to determine the presence of regeneration 
events  during  a  test.  When  an  ECU  connection  is  available,  the  information  might  be 
found within the recorded engine and after-treatment parameters. Otherwise, qualitative 
elements might help, as illustrated in Figure 14 with the increase of CO2 emissions and 
exhaust temperature, which are typical for most of the regeneration of Diesel Particulate 
Filters (DPFs). 

The  verification  of  regeneration  may  be  based  on  expert  judgement  through  cross-
correlation  of  several  of  the  following  signals,  which  may  include  exhaust  temperature, 
PN,  CO2,  O2  measurements  in  combination  with  vehicle  speed  and  acceleration.  If  the 
vehicle has a regeneration recognition feature declared in Transparency List 1 set out in 
Table  1  of  Appendix  5  to  Annex  II  of  WLTP  2nd  Act  regulation,  it  shall  be  used  to 
determine  the  occurrence  of  regeneration.  The  manufacturer  shall  also  declare  in 
Transparency  List  1  the  procedure  needed  in  order  to  complete  the  regeneration.  The 
manufacturer may advise how to recognise whether regeneration has taken place in case 
such a signal is not available. If regeneration occurred during the test, the result without 
the  application  of  either  the  Ki  -factor  or  the  Ki  offset  shall  be  checked  against  the 
requirements  of  point  3.1.0.  If  the  resulting  emissions  do  not  fulfil  the  requirements, 
then the test shall be voided and repeated once. The completion of the regeneration and 
stabilisation  through  at  least  1  hour  of  driving  shall  be  ensured  prior  to  the  start  of  the 
second test. The second test is considered valid even if regeneration occurs during it. 

Figure 14. CO2 and exhaust temperature increase during DPF regeneration (after 5000 seconds). 

2016_06_28_Test2

.

]

m
p
p
[
2
O
C
_
t
e
W

140000

120000

100000

80000

60000

40000

20000

0

0

.

]
K
g
e
d
[
p
m
e
T
t
s
u
a
h
x
E

700

600

500

400

300

200

100

0

1000

2000

3000

4000

5000

6000

7000

Time [s]

2016_06_28_Test2

0

1000

2000

3000

4000

5000

6000

7000

Time [s]

Source: JRC own development 

40 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8  Data exchange files [How to report the test data?] 

 According to the EU-RDE Regulation, Appendix 8 and its amendments regarding the 
data exchange and reporting requirements, the PEMS data files shall be structured using 
standardized  contents  and  formats.  RDE4  introduces  an  update  on  the  format  and 
contents of the data exchange files to enhance harmonization on the PEMS reporting. 

For  EU-RDE-TA  and  EU-RDE-ISC  tests,  the  contents  and  the  formats  are  strict  and 
mandatory.  For  other  types  of  PEMS  testing,  it  is  highly  recommended  to  use  the 
formatting requirements from the EU-RDE Regulation to ensure the highest compatibility 
with the data processing tools which are on the market. 

It is strongly recommended to use the .csv Sample files for Data Exchange file, Reporting 
file  #1,  and  Reporting  file  #2  that  have  been  made  available  publicly  in  CIRCABC: 
EUROPA  >  European  Commission  >  CIRCABC    >  GROW  >  wltp  >  New  light  duty  test 
procedures  >  RDE-LDV  >  rde-ldv_reference  Empty  lines  shall  be  used  in  case  some 
parameters are not reported. 

For EU-RDE-TA and EU-RDE-ISC testing, it is mandatory to verify and to record the data 
listed  as  M  in  Table  10.  The  time-series  (Table  11)  must  include  all  the  elements 
recorded  during  the  operation  of  the  instruments,  at  least  between  test-start  and  test-
end,  at  their  sample  frequency.  For  other  types  of  PEMS  testing,  the  recommended 
information is indicated with the letter O. It is recommended that the equipment used for 
testing  provides  data  in  a  way  that  complies  to  the  legislation  with  respect  to  data  file 
generation and reporting.  

Table 10. Testing conditions to be recorded 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

O 

Test ID 

Test date 

[code] 

[dd.mm.yyyy] 

Organisation supervising the test 

[name of the organisation] 

Test location 

[city (Country)] 

Organisation commissioning the test 

[name of the organization] 

Vehicle driver 

[TS/Lab/OEM] 

Table 11. Time series to be recorded 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

M 

M 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

O 

O 

O 

Start time of pre-test procedure 

[h:min] 

Start time of trip 

[h:min] 

Start time of post-test procedure 

[h:min] 

End time of pre-test procedure 

End time of trip 

[h:min] 

[h:min] 

41 

 
 
Time series to be recorded (continued) 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

M 

M 

M 

M 

M 

M 

M 

M 

- 

O 

M 

M 

O 

O 

M 

M 

M 

- 

- 

- 

- 

- 

- 

- 

- 

M 

M 

M 

M 

M 

M 

M 

M 

O 

O 

M 

M 

O 

O 

M 

M 

M 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

End time of post-test procedure 

[h:min] 

Test time 

CO2 mass (sensor) 

CO mass (sensor) 

[s] 

[ppm] 

[ppm] 

NO2 mass flow rate (sensor) (5) 

[ppm; g/s] 

NO mass flow rate (sensor) (5) 

[ppm; g/s] 

NOx mass flow rate (sensor) (5) 

[ppm; g/s] 

GNSS Vehicle speed(1) 

ECU Vehicle speed(2) 

Sensor Vehicle speed(2) 

Latitude (GNSS) 

Longitude (GNSS) 

GNSS altitude(2) 

Sensor altitude(3) 

[km/h] 

[km/h] 

[km/h] 

[deg:min:s] 

[deg:min:s] 

[m] 

[m] 

Ambient pressure (sensor) 

[kPa] 

Ambient temperature (sensor) 

[K] 

Ambient humidity (sensor) 

[g/kg; %] 

Engine speed (ECU)(3) 

[rpm] 

Engine coolant temperature (ECU)(4) 

Engine oil temperature (ECU)(4) 

Regeneration status (ECU)(4) 

Pedal position (ECU)(4) 

[K] 

[K] 

[-] 

[%] 

Vehicle status (ECU)(4) 

[error 1; normal 0] 

Engine torque (ECU)(4) 

State of charge (ECU)(4) 

[Nm] 

[%] 

1 To be determined by at least one method for EU-RDE-ISC. For EU-RDE-TA, recording the vehicle speed from 

the ECU is not permitted. 

2 To be determined by at least one method, although pressure sensor is the recommended option for retrieving 

the altitude. 

3 It is not permitted to record ECU signals to calculate exhaust mass flow during EU-RDE-TA tests. 
5 NOx may be either measured or calculated from measured NO and NO2 concentrations. 

42 

                                           
Time series to be recorded (continued) 

EU-RDE 
TA 

EU-RDE 
ISC 

Other 
PEMS 
testing 

Parameter 

Description/Unit 

- 

- 

- 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

O 

Fuel rate (ECU)(4) 

Engine fuel flow (ECU)(4) 

Engine intake fuel flow (ECU)(4) 

[g/s] 

[g/s] 

[g/s] 

O2 mass flow rate (sensor) 

[ppm; g/s] 

THC mass flow rate (sensor) 

[ppm; g/s] 

CH4 mass flow rate (sensor) 

[ppm; g/s] 

Hybrid battery State of Charge (ECU or 
power analyser) 

[%] 

Hybrid  battery  current(ECU  or  power 
analyser) 

[A] 

Hybrid  battery  voltage  (ECU  or  power 
analyser) 

[V] 

43 

 
List of abbreviations and definitions 

#/m3 

number per cubic metre 

A 

AGM 

CH4 

CNG 

CO 

CO2 

CPC 

DPF 

EC 

ECU 

EFM 

EGR 

FID 

g/kg 

g/s 

GPF 

Ampere 

Absorbent glass mat battery 

Methane 

Compressed natural gas 

Carbon Monoxide 

Carbon Dioxide 

Condensation Particle Counter 

Diesel Particulate Filter 

European Commission 

Engine Control Unit 

Exhaust mass Flow Meter 

Exhaust Gas Recirculation System 

Flame Ionization Detector 

for relative humidity, 
mass (grams) of water vapour divided by mass (kg) of dry air 

gram per second 

Gasoline Particulate Filter 

GNSS 

Global Navigation Satellite System (GNSS) 

GSI 

Hz 

K 

kg/s 

km/h 

kPa 

LDV 

LNT 

LPG 

m 

MIL 

Nm 

gear shift indicator 

hertz 

kelvin 

kilogramme per second 

kilometre per hour 

kilopascal 

Light-duty vehicle 

lean NOx trap 

Liquid Petroleum Gas 

meter 

Malfunctioning Indicator Lamp 

Newton metre 

NMHC 

non-methane hydrocarbons 

NO 

NO2 

NOx 

NTE 

OBD 

PEMS 

PN 

ppm C1 

Nitrogen Oxide 

Nitrogen Dioxide 

Nitrogen Oxides 

Not-to-exceed emission limits 

On-Board Diagnostics 

Portable Emissions Measurement System 

Particle Number 

parts per million carbon equivalent 

44 

 
ppm 

RDE 

parts per million 

Real Driving Emissions 

RDE-ISC 

Real Driving Emissions testing for In-service conformity 

RDE-TA 

Real Driving Emissions testing for Type-approval 

rpm 

SCR 

THC 

V 

revolutions per minute 

Selective Catalytic Reduction 

Total Hydrocarbons 

Volt 

VELA 

Vehicle Emissions Laboratory  

WWH-OBD  Worldwide Harmonised On-Board Diagnostics 

45 

List of figures 

Figure 1. Installation of PEMS main units left) inside the vehicle right) outside the 
vehicle ................................................................................................................ 10 

Figure 2. Vehicles equipped with a roof box (left) or loaders that modify the 
aerodynamic characteristics of a vehicle (right) are not eligible for RDE-TA and RDE-ISC 
testing. ............................................................................................................... 14 

Figure 3. left) installation of PEMS main units outside the vehicle;  centre) installation 
outside on small cars without hook;  right) securing the instruments with straps inside 
the vehicle ........................................................................................................... 23 

Figure 4. Installation of the EFM: elements for clamping .......................................... 24 

Figure 5. EFM Installation left) using a tailpipe adaptor; right) tubes and collars on a 
dual exhaust ........................................................................................................ 25 

Figure 6. left) examples of EFM installation when the PEMS main unit is installed inside 
the vehicle; right) proper signalling of the EFM ......................................................... 26 

Figure 7. Installation examples for the GNSS antenna and the weather station ........... 26 

Figure 8. left) connection to the vehicle ECU; right) secure mounting of a laptop 
connected to the OBD reader. ................................................................................ 27 

Figure 9.left) Charging of the batteries;  centre) batteries to operate the PEMS, located 
in the trunk, properly secured with straps; right) example of PEMS main unit with 
portable batteries. ................................................................................................ 27 

Figure 10. Routing heated probe left) from the inside of the vehicle; right) outside of the 
vehicle. ............................................................................................................... 28 

Figure 11. Test start sequence. ............................................................................. 34 

Figure 12. Test end sequence. .............................................................................. 34 

Figure 13. Verification of trip validity according to EU-RDE ....................................... 37 

Figure 14. CO2 and exhaust temperature increase during DPF regeneration (after 5000 
seconds). ............................................................................................................ 40 

46 

 
List of tables 

Table 1. Types of PEMS tests on light-duty vehicles and requirements ........................ 3 

Table 2. Test parameters for all vehicles ................................................................. 4 

Table 3. Test parameters specific to hybrid vehicles .................................................. 6 

Table 4. Gas and PN analysers. RDE specifications and verification ............................. 7 

Table 5. List of OBD issues making the vehicle non-eligible for RDE-TA and RDE-ISC 
tests ................................................................................................................... 11 

Table 6. Vehicle information to be reported ............................................................ 12 

Table 7. Overview of testing conditions .................................................................. 15 

Table 8. Elements to be checked before the installation of the instruments ................. 21 

Table 9. Recommended ranges for data quality screening ......................................... 39 

Table 10. Testing conditions to be recorded ............................................................ 41 

Table 11. Time series to be recorded ..................................................................... 41 

47 

 
Annex: Criteria for vehicle selection and failed vehicles decision 

Selection of vehicles for European In-Service Conformity 
emissions testing 

x = Exclusion 
Criteria 

X = Checked 
and reported 

Confidential 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

Date:  

Name of investigator: 

Location of test: 

Country of registration (in EU only): 

Vehicle Characteristics 

Registration plate number: 

Mileage: 

The  vehicle  must  have  between  15  000 
km and 100 000 km 

Date of first registration: 

The  vehicle  must  be  between  6  months 
(or  12  months  for  testing  evaporative 
emissions) and 5 years old 

VIN:  

Emission class and character: 

Country of registration: 

The vehicle must be registered in the EU 

Model: 

Engine code: 

Engine volume (l): 

Engine power (kW): 

x 

x 

x  

Gearbox type (auto/manual): 

Drive axle (FWD/AWD/RWD): 

Tire size (front and rear if different):  

Is the vehicle involved in a recall or 
service campaign? 

If  yes:  Which  one?  Has 
campaign 
done?  

the 
repairs  already  been 

x  

The repairs must have been done 

48 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
 
 
Vehicle owner interview 

(the  owner  will  only  be  asked  the  main  questions  and  shall  have  no  knowledge  of  the 
implications of the replies) 

x = Exclusion 
Criteria 

X = Checked 
and reported 

Confidential 

Name  of  the  owner    (only  available  to 
the  accredited 
inspection  body  or 
lab/technical service) 

Contact  (address  /  telephone)  (only 
available  to  the  accredited  inspection 
body or lab/technical service) 

How  many  owners  did  the  vehicle 
have? 

Did the odometer not work? 

If yes, the vehicle cannot be selected. 

Was  the  vehicle  used  for  one  of  the 
following? 

As presentation car? 

As a taxi?  

As delivery vehicle? 

For racing / motor sports? 

As a rental car? 

Has  the  vehicle  carried  heavy  loads 
over 
the 
manufacturer? 

specifications 

the 

of 

If yes, the vehicle cannot be selected. 

Have  there  been  major  engine  or 
vehicle repairs? 

Have  there  been  unauthorised  major 
engine or vehicle repairs? 

If yes, the vehicle cannot be selected. 

Has 
increase/tuning? 

there 

been 

a 

power 

If yes, the vehicle cannot be selected. 

Was  any  part  of  the  emissions  after-
treatment  and/or  the  fuel  system 
replaced? Were original parts used? 

If  original  parts  were  not  used,  the  vehicle 
cannot be selected. 

Was  any  part  of  the  emissions  after-
treatment system removed? 

If yes, the vehicle cannot be selected 

Were  there  any  unauthorised  devices 
installed (Urea killer, emulator, etc.)? 

If yes, the vehicle cannot be selected 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

x 

49 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Was  the  vehicle  involved  in  a  serious 
accident? Provide a list of damage and 
repairs done afterwards 

Have  the  car  been  used  with  a  wrong 
fuel  type  (i.e.  gasoline 
instead  of 
diesel)  in  the  past?  Have  the  car  been 
used  with  non-commercially  available 
EU-quality 
fuel  (black  market,  or 
blended fuel?) 

If yes, the vehicle cannot be selected. 

Did  you  use  air-fresher,  cockpit-spray, 
brake 
high 
hydrocarbon  emission  source  around 
the vehicle during the last month? 

cleaner 

other 

or 

If  yes,  the  vehicle  cannot  be  selected  for 
evaporative testing. 

Was there a gasoline spill in the inside 
or outside of the vehicle during the last 
3 months? 

If  yes,  the  vehicle  cannot  be  selected  for 
evaporative testing. 

Did anyone smoke in the car during the 
last 12 months? 

If  yes,  the  vehicle  cannot  be  selected  for 
evaporative testing 

Did  you  apply  corrosion  protection, 
stickers,  under  seal  protection,  on  any 
other  potential  sources  of  volatile 
compounds to the car? 

If  yes,  the  vehicle  cannot  be  selected  for 
evaporative testing 

Was the car repainted? 

If  yes,  the  vehicle  cannot  be  selected  for 
evaporative testing 

Where  do  you  use  your  vehicle  more 
often? 

% motorway 

% rural 

% urban 

Did  you  drive  the  vehicle  in  a  non  EU 
Member  State  for  more  than  10%  of 
driving time? 

If yes, the vehicle cannot be selected 

In  which  country  was  the  vehicle 
refuelled during the last two times? 

If  the  vehicle  was  refuelled  the  last  two 
times  outside  a  state  applying  the  EU  Fuel 
Standards, the vehicle cannot be selected. 

x = Exclusion 
Criteria 

X = Checked 
and reported 

Confidential 

x 

x 

x 

x 

- 

x 

x 

x 

x 

x 

x 

x 

x 

50 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Has  a  fuel  additive,  not  approved  by 
the manufacturer used? 

If yes then the vehicle cannot be selected. 

Has  the  vehicle  been  maintained  and 
used  according  to  the  manufacturer's 
recommendations? 

If not, the vehicle cannot be selected. 

Full 
including any re-works 

service 

and 

repair  history 

the 

If 
provided, the vehicle cannot be selected. 

full  documentation  cannot  be 

x = Exclusion 
Criteria 

X = Checked 
and reported 

Confidential 

x 

x 

x 

51 

 
 
 
 
 
 
 
 
 
Vehicle examination and maintenance 

X= Exclusion 
Criteria / 

F= Faulty 
Vehicle 

X=checked and 
reported 

Fuel  tank  level  (full  /  empty)  Is  the  fuel  reserve 
light ON? 

If yes, refuel before test. 

Are  there  any  warning  lights  on  the  instrument 
panel  activated  indicating  a  vehicle  or  exhaust 
that 
after-treatment  system  malfunctioning 
cannot  be  resolve  by  normal  maintenance? 
(Malfunction  Indication  Light,  Engine  Service 
Light, etc.?) 

If yes, the vehicle cannot be selected 

Is the SCR light on after engine-on? 

If  yes,  the  Ad  Blue  should  be  filled  in,  or  the  repair 
executed before the vehicle is used for testing. 

Visual  inspection  exhaust  system  Check  leaks 
between  exhaust  manifold  and  end  of  tailpipe.  Check 
and document (with photos) 

If  there  is  damage  or  leaks,  the  vehicle  is  declared 
faulty. 

Exhaust  gas  relevant  components  Check  and 
document 
relevant 
(with  photos)  all  emissions 
components for damage. 

If there is damage, the vehicle is declared faulty.  

Evaporative system 

Pressurize fuel-system (from canister side), testing for 
leaks in a constant ambient temperature environment, 
FID sniff test around and in the vehicle 

If  the  FID  sniff  test  is  not  passed,  the  vehicle  is 
declared faulty.  

Fuel sample Collect fuel sample from the fuel tank. 

Air  filter  and  oil  filter  Check  for  contamination  and 
damage  and 
if  damaged  or  heavily 
contaminated  or  less  than  800  km  before  the  next 
recommended change. 

change 

Window  washer  fluid  (only  for  evaporative 
testing Remove window washer fluid and fill tank with 
hot water. 

Wheels (front & rear) Check whether the wheels are 
freely moveable or blocked by the brake. 

If not, the vehicle cannot be selected. 

Tyres (only for evaporative testing) Remove spare 
tyre,  change  to  stabilised  tyres  if  the  tyres  were 
changes less than 15.000 km ago. Use summer and all 
season tyres only. 

52 

x 

x 

F 

F 

F 

x 

x 

x 

x  

x 

x 

  
  
 
  
  
 
  
 
 
  
 
X= Exclusion 
Criteria / 

F= Faulty 
Vehicle 

X=checked and 
reported 

F 

F 

F 

x/F 

x 

x 

Drive  belts  &  cooler  cover  In  case  of  damage,  the 
vehicle is declared faulty. Document with photos 

Check  fluid  levels  Check  the  max.  and  min.  levels 
(engine oil, cooling liquid) / top up if below minimum 

Filler  flap  (only  for  evaporative  testing)  Check 
overfill  line  within  filler  flap  is  completely  free  of 
residues or flush the hose with hot water. 

Vacuum  hoses  and  electrical  wiring  Check  all  for 
integrity. 

In  case  of  damage,  the  vehicle  is  declared  faulty. 
Document with photos 

Injection valves / cabling Check all cables and fuel 
lines.  

In  case  of  damage,  the  vehicle  is  declared  faulty. 
Document with photos 

Ignition cable (gasoline) Check spark plugs, cables, 
etc. In case of damage, replace them. 

EGR  &  Catalyst,  Particle  Filter  Check  all  cables, 
wires and sensors.  

In  case  of  tampering,  the  vehicle  cannot  be  selected. 
In  case  of  damage    the  vehicle  is  declared  Faulty, 
Document with photos 

Safety  condition  Check 
tires,  vehicle’s  body, 
electrical  and  braking  system  status  are  in  safe 
conditions for the test and respect road traffic rules. 

If not, the vehicle cannot be selected. 

Semi-trailer  Are  there  electric  cables  for  semi-trailer 
connection, where required?  

Aerodynamic  modifications  Verify  no  aftermarket 
aerodynamics  modification  that  cannot  be  removed 
before  testing  was  made  (roof  boxes,  load  racking, 
spoilers,  etc.)  and  no  standard  aerodynamics 
components  are  missing  (front  deflectors,  diffusers, 
splitters, etc.). 

If  yes,  the  vehicle  cannot  be  selected.  Document  with 
photos.  

Check  if  less  than  800  km  away  from  next 
scheduled  service,  if  yes,  then  perform  the 
service. 

All  checks  requiring  OBD  connections  to  be 
performed before and/or after the end of testing  

Powertrain  Control  Module  calibration  part 
number and checksum  

53 

x 

x 

x 

x 

x 

x 

  
  
 
  
  
  
  
  
  
  
  
  
  
  
X= Exclusion 
Criteria / 

F= Faulty 
Vehicle 

X=checked and 
reported 

x 

x 

OBD  diagnosis  (before  or  after  the  emissions 
test) Read Diagnostic Trouble Codes & Print error log 

OBD  Service  Mode  09  Query  (before  or  after  the 
emissions  test)  Read  Service  Mode  09.  Record  the 
information. 

OBD mode 7 (before or after the emissions test) 
Read Service Mode 07. Record the information 

Remarks 
components / part numbers 

for:  Repair  / 

replacement 

of 

54 

  
  
 
 
  
  
 
GETTING IN TOUCH WITH THE EU 

In person 

All over the European Union there are hundreds of Europe Direct information centres. You can find the 
address of the centre nearest you at: http://europea.eu/contact 

On the phone or by email 

Europe Direct is a service that answers your questions about the European Union. You can contact this 
service: 

- by freephone: 00 800 6 7 8 9 10 11 (certain operators may charge for these calls), 

- at the following standard number: +32 22999696, or 

- by electronic mail via: http://europa.eu/contact 

FINDING INFORMATION ABOUT THE EU 

Online 

Information about the European Union in all the official languages of the EU is available on the Europa 
website at: http://europa.eu 

EU publications 
You can download or order free and priced EU publications from EU Bookshop at: 
http://bookshop.europa.eu. Multiple copies of free publications may be obtained by contacting Europe 
Direct or your local information centre (see http://europa.eu/contact). 

 
 
 
 
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doi:10.2760/08294 

ISBN 978-92-79-77345-7