Smoke detector having charged electrodes in vented space - has one electrode heated and other acting as collector electrode

摘要

Ionisation process consists of introducing particles into a space in which electrons are emitted at a speed sufficient to ionise the particles but not sufficient to ionise the air in the space. This space is subjected to an electrical field of sufficient intensity and polarity to cause the electrons to be driven back to their source of emission. The ions thus produced are collected.