Mitsubishi Cable Industries, Ltd.

Tatsuno Corporation

Tokyo Tatsuno Co., Ltd.

Yasuo Shiraiwa

Toshio Kudo

Masaaki Nagai

Yasuo Ijiri

A low molecular weight organic liquid leakage detection system comprising plural sensors capable of showing an electrical resistance variation upon contact with a low molecular weight organic liquid, said sensors being installed at every possible leakage site, being electrically connected in series, and being electrically further connected to an electric resistance detector. The detection system of the present invention is advantageous in that it permits precise and efficient detection of low molecular weight organic liquid leakage, with no need to provide a long sensor over the entire detection area.

Low molecular weight organic liquid leakage detection system

A low molecular weight organic liquid detection sensor which is a wire body formed by coating a core material with a conductive layer made of a substantially non-crosslinked material having a Shore A hardness not more than 70 which is mainly composed of thermoplastic elastomer and conductive carbon, the conductive layer varying in its electric resistance upon contact with a low molecular weight organic liquid. The sensor of the invention permits secured mechanical strength, its easy installation in a narrow conduit or over a wide area, and highly sensitive sensing of a low molecular weight organic liquid in the longitudinal direction. The detector of the invention comprises a sensor having the above structure, preferably a porous body which houses and protects the sensor, a means which is connected to this sensor and detects electric resistance variation, and a means for transmitting this electric resistance variation as an alarm signal, and the detector can be used in the presence of underground water, which in turn permits use of existing liquid-leakage detection holes and installation at low costs.

Low molecular weight organic liquid detection sensor in the shape of a

The invention provides a sensor whose conductive sheet is composed of substantially non-cross-linked thermoplastic elastomer and conductive carbon. The conductive sheet has a maximum of 70 of Shore A-hardness. By virtue of the above structure, the sensor very sharply responds to electric resistance of the conductive sheet against presence of low molecular weight organic liquid such as gasoline and vapor thereof to quickly detect leaked organic liquid or vapor with extremely sharp sensitivity. Furthermore, the detection system of the invention using the above sensor has a simple circuit which precisely detects varied electric resistance of the conductive sheet. The detection system characteristically incorporates an alarm generator to instantly warn operators of the presence of leaked organic liquid such as gasoline and vapor thereof.

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Tokyo, Japan

Yasuo Shiraiwa