“The measure is mainly aimed at removing fraudsters, people who deliberately drive around with a defective particulate filter or who deliberately remove their particulate filter, from the technical inspection,” says Flemish minister Lydia Peeters (Open Vld).
In the particulate filter test, a particle counter (PN counter) is used on diesel vehicles with Euro standard 5 and higher. If your vehicle emits more than 1 million particulate matter per cubic centimeter, you will receive a red card. The particulate filter is then defective or removed and must normally be repaired or replaced within 15 days.
Vehicles in the zone between 250,000 and 1 million soot particles will receive a green card with a warning (there were 1,861 in July). If your vehicle emits less than 250,000 particulate matter per cubic centimeter, you will receive a green card.
“With recent diesel engines (Euro 5 and 6) the soot particles are so miniscule that they could no longer be measured with the classic soot test or ‘opacity measurement’. But even those small soot particles remain just as dangerous for our health and the environment and climate. Hence the switch to the new measuring technology since 1 July this year,” says Sofie Vanhout of Goca Vlaanderen.
A number of drivers meanwhile complain that the test is too strict and unreliable, because the values can deviate greatly from multiple tests. For example, a reader signals to us that more than 2,000,000 particulate matter particles were measured the first time, 1,600,000 immediately afterwards and 1,200,000 the third time.
“Of course there is a measurement tolerance on every measurement with our calibrated devices, but it is certainly not as great as indicated here. The result will certainly not continue to fall, unless of course an intervention – cleaning or replacement – is carried out on the particulate filter in the meantime. In addition, the measurement results are also determined by the condition of the engine. A properly functioning engine has stable combustion and therefore even emissions,” says Goca Vlaanderen.
In other words: if more than 1 million particulate matter are measured, you can without a doubt assume that the particulate filter is no longer working properly.
It is mainly slightly older vehicles with Euro standard 5a that are rejected. These are cars that date from before January 1, 2013.
Another thing: it is now clear that rinsing the particulate filter after a rejection is often not enough to still receive a green card in the event of a re-inspection. “A particulate filter of a certain age often has to be replaced in order to comply with current environmental standards. However, because garage owners are experiencing difficulties in obtaining new particulate filters, the period of 15 days that is foreseen to put the vehicle in order has been temporarily extended to 3 months,” says Vanhout.