METHOD OF MEASUREMENT OF ION CURRENT BETWEEN SPARK PLUG ELECTRODES IN INTERNAL COMBUSTION ENGINE Russian patent published in 1998 - IPC

FIELD: transport engineering; diagnosing of combustion processes in cylinders of internal combustion engine; automobile diagnostic devices. SUBSTANCE: to measure ion current between spark plug electrodes constant measuring voltage is supplied to spark plug electrodes of engine ignition system, and ion current flowing through spark plug electrodes is measured. In proposed method voltage pulses with preset parameters (amplitude, relative pulse duration and frequency) are formed and measuring capacitor is charged with pulses, thus formed, measuring capacitor being connected in parallel with spark plug electrodes. Ion current is measured as value of charge current of measuring capacitor. EFFECT: improved interference protection, high accuracy of ion current measurement. 5 dwg