What is a PTI-PN test?


The PTI-PN test was developed for the inspection of particulate filters on diesel-powered vehicles. The test is conducted by performing a particle test, using a particle counter. The test, during which particle concentration levels are measured for a period of 90 seconds, also establishes if the particulate filter has been removed.


In this video a Peugeot Bipper (2011) with 213,312 kms on the clock is tested in a PTI-PN test.


When will the PTI-PN test be introduced in the Netherlands?


The PTI-PN test will be obligatory in the Netherlands as of 1 January 2023, and apply to all diesel-powered passenger cars, vans and lorries fitted with a diesel particulate filter (DPF). As the existing OBD (on-board diagnostics) and exhaust gas opacity tests for these vehicles are unable to establish whether the particulate filter is present and working correctly, these tests will be superseded by the particle test.


The PTI-PN test and PTI threshold limit value (TLV)


The PTI-PN test takes approximately 90 seconds, and is carried out with the engine idling. The test may be conducted on a cold engine, or when the engine is at operating temperature. A particle counter is used to measure particle concentration levels in the exhaust gas. As the counter is able to measure very low concentrations, the condition of the particulate filter can be accurately determined.

The Dutch PTI threshold limit value (TLV) for all vehicles is 1,000,000 (one million) particles per cubic centimetre of air (#/cm3).


Checking a functioning diesel particulate filter (DPF)


The image below shows particulate emissions for a Euro 5 diesel vehicle, measured over a prolonged period of time. At the start of the test, the particle counter draws in and measures the particle concentration of ambient air (1,900 to 2,600 particles//cm3 or #/cm). Next, the sampling probe is placed in the exhaust, with the engine idling. The initial particle concentration level is 4,000 #/cm3. During the next 450 seconds, this level drops to less than 100 #/cm3. When the sampling probe is removed from the exhaust, the counter again draws in ambient air, and particle concentration level increases to 2,000 #/cm3. The test demonstrates the high filtration efficiency of diesel particulate filters (DPFs). It is noted that particulate emissions are lower when the engine is at operating temperature.


When will the PTI-PN test be introduced in other countries?


At this stage, the PTI-PN test is voluntary for EU member states. It is expected that a growing number of member states will introduce the test over the coming years. However, as individual states are able to define their own PTI criteria, the particle test, the configuration of the particle counter, and the threshold limit value (TLV) may differ from one country to the next.


In March 2021, Belgium decided to introduce a PTI-PN test for cars and vans, which will take effect as of 1 July 2022.


The German Federal Ministry of Transport and Digital Infrastructure decided in 2017 to introduce a PTI-PN test for Euro 6/VI diesel vehicles. In March 2021 the final date for introduction of the PTI-PN test was published. From 2023 all German Euro 6/VI vehicles will be tested.


In February 2022, Switzerland decided to introduce a PTI-PN test for cars, vans and trucks which will take effect as of 1 January 2023.


Other EU member states have shown a considerable interest in the PTI-PN test, and both the European Commission and the United Nations (UNECE) have placed it on their agenda. In addition, authorities in Spain, Israel, Chile, Peru, Mexico, Colombia, South Korea and Japan are in the process of researching and/or introducing a PTI-PN test.

An up-to-date overview of the introduction of the PTI-PN test is available here.