PTI particle number test introduced by the European Commission as a Recommendation

31 March 2023                         Source: European Commission


Over the past year, the European Commission has been working on a Recommendation for the PTI particle number test that incorporates knowledge and experience from the Netherlands, Belgium and Germany. Emission Training Services, the owner of this website, formed the basis of this development on behalf of the Ministry of Infrastructure and Water Management and advised the authors. The Recommendation can be downloaded from the EU website. It focuses in particular on the specification of the particle counter. The particle number test and limit values ​​are also described. European member states now have a handle and can voluntarily introduce the PTI particle number test.


PTI particle number test to world level

24 February 2023                    Source: UNECE


Until now, the PTI particle number test has been a national matter. Belgium, the Netherlands, Switzerland and Germany have recently or soon started working with it, but preparations are also being made at European and global level.

A United Nations working group (IWG-PTI) submitted a proposal for a PTI particle number test at the January 2023 meeting of the WP.29/GRPE working group. This proposal is an adaptation/extension of the existing resolution R.E. 6. Such a resolution is not binding but can be seen as a guideline to which countries that have ratified the 1997 Agreement can refer and act. ETS has largely written this proposal on behalf of the Dutch Ministry of I&W for the working group IWG-PTI.

The WP.29/GRPE Working Group is considering the proposal.


PTI particle number test shows quality diesel particulate filters

2 January 2023                         Source: ETS & Van Abeelen


Do diesel particulate filters continue to function properly at higher mileages? And how many have been removed? No one has an answer to these questions because no suitable test method existed. The new particle number test in a Periodic Technical Inspection (PTI) will change this on January 1, 2023.

PTI specialist Van Abeelen and GOCA in Belgium have already measured in 2022. In this article, results of PTI particle tests of 586 Dutch vehicles and more than 300,000 Belgian vehicles are analysed and discussed.

Vehicle age, mileage and the different car brands appear to be important parameters. The particulate filter of the majority of younger vehicles is in order. On the other hand, we should be concerned about 'the last 10 to 15% mostly older vehicles' that have too high particulate emissions.

The rejection rate based on the new particle number test increases as vehicles get older.


Download the full article below

ETS Van Abeelen Particle Test Shows Quality DPF Technology
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Introduction of particulate filter check in the Netherlands postponed to January 1, 2023

16 June 2022                           Source: Dutch Ministry of Infrastructure & Water Management


Due to insufficient availability of parts for the production of particle counters, not all PTI stations will have a particle counter on 1 July 2022. That is why the State Secretary has decided to postpone the introduction of the particulate filter check by 6 months. Suppliers of particle counters expect to have delivered the required number of particle counters by the end of 2022. From January 1, 2023, the particulate filter check will be a mandatory part of the Dutch PTI for diesel vehicles equipped with an ex-works particulate filter.


Switzerland to introduce PTI-PN test on 1 January 2023.

1 March 2022                          Source: ASTRA


The Swiss authorities have announced the introduction of a PTI-PN test for Euro 5b and 6 cars and vans and Euro VI trucks. The test will come into effect on 1 January 2023. The PTI threshold limit value has been set at 100,000 (one hundred thousand ) particles per cubic centimeter at low idle speed (fast pass) or 250,000 particles per cubic centimeter at 2000 rpm.


Particles Matter has been published.

25 February 2022                 Source ETS


'Particles Matter' describes the new Particulate Filter Check for periodic technical inspections that will be introduced in The Netherlands, Belgium and Germany. By answering 92 questions, Particles Matter explains the PTI-PN test, the Particle Number (PN) counter, and the complex technical ins and out of the DPF. The book is intended for PTI inspectors, mechanics, policymakers and other interested parties.


For more information click here or go to the webshop.


Germany to introduce PTI-PN test on 1 January 2023.

19 June 2021                        Source: Verkehrsblatt

8 July 2021                           Source: PTB

After The Netherlands and Belgium, Germany has now also passed a law to introduce particle number measurement into the periodic technical inspecion. Starting from January 2023, the PTI-PN test will only be introduced for Euro 6/VI diesel vehicles (cars and commercial vehicles). The new measurement method will replace the opacity (smoke) measurement for the vehicles concerned.

The PTI-PN test procedure was published in Verkehrsblatt number 8 in Amendment 86  on 30 April 2021, Änderung der Richtlinie für die Durchführung der Untersuchung der Abgase von Kraftfahrzeugen nach Nummer 6.8.2 der Anlage VIIIa Straßenverkehrs-Zulassungs-Ordnung (StVZO) (AU-Richtlinie)

The specification of the particle counter was published on July 8th, 2021 by the Physikalische Technische Bundesanstalt in document PTB-A 12.16 Partikelzähler

The specification  of the calibration of the PN-counter was published in Verkehrsblatt number 11 in Amendment 133  on 15 June 2021, Richtlinie zur Kalibrierung von Abgasmessgeräten, die für die Untersuchung der Abgase von Kraftfahrzeugen nach Nummer 6.8.2 der Anlage VIIIa StVZO eingesetzt werden (“AU-Geräte Kalibrierrichtlinie“)


The book 'Roet in beeld' has been published.

11 June 2021                      Source: ETS


'Roet in beeld' describes the new PTI-PN test for periodic technical inspections that will be introduced in The Netherlands and Belgium on 1 July 2022. In December 2021 the English translation titled "Particles Matter" will be published.


For more information click here or go to the webshop.


Belgium to introduce PTI-PN test on 1 July 2022.

31 March 2021                          Source: VRT


The Belgian authorities have announced the introduction of a PTI-PN test for Euro 5 and 6 cars and vans. The test will come into effect on 1 July 2022. The PTI threshold limit value has been set at 1,000,000 (one million) particles per cubic centimetre for both vehicle types.


PTI-PN test to be introduced in the Netherlands on 1 July 2022.   

20 January 2021                          Source: Staatscourant


Authorities amend Vehicles Regulation (Road Traffic Act). New PTI-PN test for diesel-powered cars, vans and lorries to be included in Dutch PTI as of 1 July 2022.


Germany postpones the introduction of PTI-PN test.

4 September 2020                        Source: Der Spiegel


German authorities have postponed the introduction of a PTI-PN test, originally planned for 1 January 2021. More time is needed to define the calibration procedures for the particle counter. The new PTI-PN test is not expected before the middle of 2023.


Institute for Metrology and Technology (NMi) issues first type approval for particle counter.

10 July 2020                                 Source: NMi


NMi-Certin has granted Dutch manufacturer TEN type approval for its PTI particle counter.


No more broken and discarded soot filters on Dutch roads.

3 December 2019                        Source: TNO press release


The introduction of a PTI-PN test will ensure that faulty particulate filters are repaired or replaced. If remedial measures are not viable, vehicles may even be taken off the road. It is expected that the introduction of a PTI-PN test will cause effective emissions from diesel vehicles fitted with a DPF to fall by 40 to 50%, while total PM emissions from vehicles in the Netherlands will be reduced by approximately 8%.


Dutch to check particulate filter during roadside vehicle inspections.

21 November 2019                      Source: Staatscourant


Authorities in the Netherlands have amended the Vehicles Regulations (part of the Road Traffic Act). The development and implementation of a particle test for diesel-powered cars, vans and lorries fitted with a DPF also allows vehicle particulate emissions to be checked during roadside inspections.


Parliamentary motion Hoogland / Van Tongeren.             

29 October 2015                         Source: Staatscourant


The Dutch Lower House has requested the government to introduce an effective method for testing harmful exhaust emissions during the periodic technical inspection (PTI) of diesel vehicles with a particulate filter.