DETECTEUR DE FEU ET SYSTEME DE PROTECTION ET ALARME CONTRE LE FEU DE LIGNE

摘要

A fire detector is provided with an electric insulator consisting of short segments of preferably a ceramic pipe disposed end-to-end within the space between an inside cylindrical electrode and cylindrical outside electrode. The inside electrode together with the insulator segments are covered with a thin salt-based layer and are disposed in the interior of the outside electrode so that between the insulator segments and the internal wall of the outside electrode an air space is formed along the length of the detector, whereby the insulator segments each provide a point-type contact between the internal wall of the outside electrode and the thin salt-based layer.