| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum switch which can be operated when a prescribed degree of vacuum is reached and to provide a vacuum evacuation device using the vacuum switch as well as to provide an ion-type vacuum gage. SOLUTION: A switching element 18 which is composed of a fixed-side contact 16 and a movable-side contact 17 is installed so as to face an environment which is changed to a vacuum from atmospheric pressure, the contact 17 is formed of a shape-memory alloy or a bimetal, a heating means 20 is installed at the contact 17, the contact 17 is always opened with reference to the contact 16, it is maintained at an operating temperature or less by exhausted heat due to convection under an atmospheric pressure environment, and it is set at the operating temperature or more when the exhausted heat is cut off under a vacuum environment. The contact 17 is deformed, and the switching element 18 is closed.
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