Hitachi, Ltd.

Shikoku Electric Power Co., Inc.

Ictitaro Tani

Katuo Sugawara

Etsunori Mori

Hideo Tsukioka

Shigeo Shiono

Etsuo Ohe

Seiichi Sakai

Toshihiko Gange

A gas chromatographic apparatus having at least two gas separation columns arranged in parallel to each other, the outlet of the first gas separation column being connected to a gas sensor through a column switch valve, and the outlet of the second gas separation column being connected to the column switch valve through a gas detection time-controlling pipe, where when the first gas separation column is communicated with the gas sensor, the outlet of the second gas separation column is made open to the atmosphere by the column switch valve, or when the second gas separation column is communicated with the gas sensor, the outlet of the first gas separation column is made open to the atmosphere by the column switch valve, or the apparatus having a first gas separation column whose inlet is connected to the switch valve and at least two second columns whose inlets are connected to the outlet of the first gas separation column, whose outlets are connected to the gas sensor and which are arranged in parallel to each other through the column switch valve, where the first gas separation column, one of the second columns and the column switch valve are communicated with each other, by the column switch valve. A chromatogram with distinctly separated peaks in a continued state can be obtained in a short time by only one detecting and recording means.

Gas chromatographic apparatus

In an apparatus for detecting gas components in the oil in an oil-filled device, which comprises a gas-storing chamber being provided at an oil-filled device containing an insulating oil through a gas-permeating material capable of separating gas components from the insulating oil, a gas calibration tube being provided at the gas-storing chamber through a switch valve, and a gas chromatographic device connected to the gas calibration tube through the switch valve, any influence of gas components in a subatmospheric pressure is eliminated and exact concentrations of gas components are detected by providing at least one stirring mixer having at least one throttle perforation in a carrier gas passage for supplying the gas components from the gas calibration tube to the gas chromatographic device at the upstream side of a gas separation column of the gas chromatographic device, or by proving a circulation passage between the gas-storing chamber and the gas calibration tube, a valve capable of being exposed to the atmosphere at the circulation passage, and a gas circulation unit at the circulation passage for circulating the gas in the circulation passage.

Method and apparatus for detecting gas components in oil in oil-filled

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Kitaibaraki, Japan

Ictitaro Tani