Mass flow measuring apparatus

摘要

Mass flow measuring apparatus includes ionizing electrodes and an ion collecting electrode located downstream of the ionizing electrodes where the ionizing electrodes are biased with a high DC voltage produced in response to ignition pulses of an internal combustion engine. The high voltage is derived from a tap of the secondary winding of the ignition coil of the ignition circuit. The ions are allowed to migrate at the same speed with the mass fluid flow an are collected by the collecting electrode. The transit time of the ions over the distance between the ionizing electrodes and the collecting electrode is measured. The period of the high DC voltage applied across the ionizing electrodes may be controlled in accordance with the magnitude of the load of the engine and/or the transit time of the ions.