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Diesel Exhaust Particle Counter from KNESTEL Made in Germany

Particle measurement on diesel vehicles and the associated particle measurement technology is currently moving into focus and will be part of the main inspection of diesel vehicles in Germany in the future through the legal innovations.

Particle measurement as part of the main inspection for diesel vehicles will come into force on January 1, 2023. The basis for this was the release and publication of the device specification for particle counters PTB-A 12.16 by the Physikalisch-Technische Bundesanstalt (PTB), which recently took place. Thus, all formal requirements have now been met to enable the introduction at the beginning of 2023.

The counting of soot particles as a fixed component of the exhaust emission test of diesel passenger cars and the resulting identification of defective and missing particle filters should ensure better air in cities and is another important step for intensified climate protection. In the future, the particle count in diesel exhaust will make it possible to determine whether and how effectively a diesel vehicle’s particle filter is still functioning. The limit will be 250,000 particles per cubic centimeter of exhaust gas. New measurement systems are needed to enable particle measurement. This is where KNESTEL Technologie & Elektronik from Hopferbach launches its market-ready, modular particle measurement technology consisting of a charging module, sensor module, ion separator and Volatile Particle Remover (VPR). The modules can be used as an OEM solution or in the form of pre-assembled modules, so adaptation to individual requirements is also no problem. The innovative particle measurement technology complies with PTB-A specifications and can therefore be used throughout Europe without any worries. It can also be easily cleaned and the diffusion charging requires, among other things, no consumables / liquids.

The measurement technology is based on the basic principle of detecting charged particles via induced currents in a sensor. For this purpose, a three-stage modular design was realized. In the first assembly, the diffusion charger, ions are generated in particle-free air by means of pulsed corona discharge and mixed with the exhaust gas to be measured in a mixing chamber, where they collide with the soot particles and charge them. The second assembly is an ion and particle separator, in which excess ions are completely separated and particles are partially separated via a clocked electric field. The third assembly is a sensor module functioning as a Faraday cage through which the charged particle clouds flow. The charged particles cause a shift of the charges in the Faraday cage, which can be measured in the form of a very low current signal. To remove volatile particles (volatile components in the exhaust gas), a fourth assembly is connected upstream of the sensor modules.

Particular challenges in particle measurement in exhaust gas are sample conditioning, reduction of particle losses, minimization of contamination with regard to maintenance intervals and the correction of size-dependent effects. Through constructive measures as well as implementation of a complex measurement process, all these requirements can be adequately considered and implemented, so that particle measurement technology from KNESTEL meets even demanding specifications.

As experts for OEM gas analysis solutions, KNESTEL brings extensive know-how in gas analysis, here the in-house smart development department for gas sensor technology and electronic components is combined with a technically modern equipped production at the location in the Allgäu. This ensures on-time production and delivery of required particle measurement technology by KNESTEL’s launch date.