Importance

Loading Importance Indicators...

Abstract

The present invention relates to an improvement of an ionizing smoke sensor having one radiation source and a two chambered structure consisting of an internal ionization chamber housing an internal electrode having a radiation source and defined by an intermediate electrode, and an external chamber where smoke can flow in, defined by an external electrode and irradiated from the radiation source through an opening in the intermediate electrode. Hitherto, in an ionizing smoke sensor having one radiation source and a two chambered structure, there has been a problem in that the giving of misinformation and noinformation occur when a little amount of thread, moisture or dust invades or a current of air flows an internal ionization chamber through an opening and an external ionization chamber. In addition, the electric field in the internal ionization chamber loses its homogeneity because of the opening, hence V-I characteristics preferable for the internal ionization chamber can not be obtained. Furthermore, stable V-I characteristics can not be obtained since hardly any smoke can hardly flow into the internal ionization chamber because of the mesh structure. In the ionizing smoke sensor of the present invention, the above described problems are solved by forming the opening part in the intermediate electrode with a mesh structure having a rate of porosity more than or equal to 50%.

Loading the Abstract Image...

First Claim