Mitsubishi Denki Kabushiki Kaisha

Katsu Ujita

Masahiro Kobayashi

Tadao Minagawa

Mitsumasa Imataki

Takeo Yoshioka

Tsutomu Egashira

A lightning arrester monitor which consists of an oxygen gas sensor provided in a lightning arrester having a zinc-oxide-type element made of zinc oxide, the main component thereof, and other oxides added thereto, the oxygen gas sensor measures the oxygen concentration of the element which increases as degradation thereof goes on. The monitor makes it possible to assess degradation of the zinc-oxide-type element with ease, without requiring any complicated electrical circuit for detecting leakage current.

Lightning arrester monitor

A protective device for protecting from abnormal voltage such as a lightning arrester comprises an earthing cylindrical metallic casing; an electrode or conductive substrate which is disposed to the direction of the axis of the metallic casing; an insulating pipe which is in spread-out shape and is disposed between the metallic casing and the electrode or the conductive substrate; and a plurality of non-linear resistors which are disposed in said insulating pipe wherein said non-linear resistors are respectively connected so as to be substantially similar to the potential distribution in said metallic casing.

Growing community of inventors

Amagasaki, Japan

Katsu Ujita