Patent ID: 8332161
Filing Date: 2012-12-11
Classification: G01N

Abstract:
1. A method for detecting a level of contamination of a particle sensor, comprising: providing a particle sensor having two electrodes situated on an insulator material for generating an electrical field; heating the insulator material to above a predetermined limiting temperature, wherein the insulator material begins to become conductive starting at the predefined limiting temperature; modulating the temperature of the insulator material by at least one of heating and cooling the insulator material between a lower temperature and an upper temperature of a modulation range, wherein both the lower temperature and the upper temperature of the modulation range are above the predetermined limiting temperature; measuring a variation over time of a measuring signal detected between the electrodes during the modulation; compensating the measured variation over time of the measuring signal using a theoretical variation over time of the measuring signal in a contamination-free state of the particle sensor, taking a temperature-dependent conductivity of the insulator material into account, in order to obtain a variation over time of a differential signal; and evaluating the differential signal for determining the level of contamination of the particle sensor.