Effect of Operation Pressure on the Response of ePNC Particle Number Concentration Sensor

Abstract

In this article, we present a method that aims toward an ideal number concentration response of a diffusion charger and diffusion collector-based particle sensor (Dekati ePNC) by using reduced pressure conditions in the sensor. A model is derived for the charger and diffusion collector stage of the sensor, as well as for the total particle number concentration (PNC) response. The derived model is validated with experimental characterization measurements in different operation pressures. The experimental results show that reduced operation pressure makes the sensor response less dependent on particle size, approaching pure particle number response. The obtained results improve the feasibility of the diffusion charging-based method in the measurement of PNC.