FIRE ALARM AND ELECTRODE DEVICE THEREFOR

摘要

Fire alarm with a measure chamber (9, 9') limited by two electrodes (1, 2), an electric field being generated between the electrodes by a direct voltage source. The measure electrode (1) has no direct connection with the direct voltage source (4) at the input of a current measuring unit (3). As soon as smoke laden particles enter the measure chamber (9) between the electrodes, the electric field causes a displacement of positive and negative particles. Due to said charge displacement (charge drift), a current is induced in the measure electrode, current which is measured.