Combustion process monitoring method e.g. for petrol engine, involves measuring the high-frequency current and high-frequency voltage for ascertaining impedance of ignited mixture

摘要

A method for monitoring a combustion process involves ignition of a fuel-air-mixture with a high-frequency plasma (50) in which a high-frequency signal is applied to a resonator (36) at a power which is so small that no electrical spark-over occurs at the electrodes. The high-frequency current and the high-frequency voltage are measured, from which the impedance of the ignited mixture is ascertained and the combustion process assessed on the basis of the impedance.