Hochiki Corporation

Tadashi Sugiyama

Yuichiro Yamamoto

Yukio Yamauchi

Takeshi Tanigawa

Yoshinori Kaminaka

Hiroshi Ito

Yoshifusa Saito

Shunichi Shoji

A gas sensor and a method for detecting a small amount of a gas such as CO contained in air entering a space between electrodes ionized by a radiation source. At least one radiation source is provided for ionizing at least a part of the space between the electrodes disposed so as to oppose each other and a radio d/x of a distance d cm between the electrodes to a field strength x V/cm of the ionized space is set to be 0.4 or more so as to obtain a change in the ionic current sufficient to realize gas sensing based on the formation of cluster ions within the ionized space.

Gas sensor and gas detecting method

Disclosed herein is an improved composite-type heat-system fire sensing device consisting essentially of a differential sensing element and constant-temperature sensing element, capable respectively of actuating a pair of electric contacts. These two type of sensing elements used in customary devices are difficult to assemble and to adjust. There are also serious problems for production and wider utilization of the sensing device. Further, the elements lack practical utilizability as well as reliability. The sensing device of this invention overcomes the abovementioned problems of the customary devices by effecting sensitivity matching of different operation characteristics of the two sensing elements, and makes it possible to optionally and freely adjust the sensitivity of the sensing device as required in accordance with the conditions of the place of installation of the sensing device so as to ensure a higher reliability and wider application of the sensing device.

Composite-type heat-system fire sensing device

Growing community of inventors

Tokyo, Japan

Tadashi Sugiyama