Design principles for diffusion chargers sensing particle number concentration

Diffusion Charging (DC) is the most promising technology for on-board determination of particle number concentration of automotive exhaust. We investigated three different measurement configurations that are based on DC, using an analytical non-dimensional model, as well as a multiphysical 3D simulation. A modulated precipitation configuration showed the best performance with respect to particle size dependency of the sensor response. Further experimental work is ongoing to validate the findings.