| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method and an apparatus for cleaning up helium for the purpose of greatly reducing the time for sweeping up He residing in a fore-line piping, using an auxiliary exhaust pump. SOLUTION: A main exhaust pump 5 has an exhaust hole connected to an auxiliary exhaust pump 6 through a fore-line piping 7 and has an intake hole connected to an analyzer tube 4, and an exhaust pipe line 9 connected to a test port 8 is connected through the main exhaust pump or directly to the fore- line piping, thus constituting a He detector for detecting He flowing in the exhaust pipe line, using the analyzer tube. Before opening the test port, a clean up gas rarely contg. exhaust gas is controlled to flow once or more times into the fore-line piping, thereby cleaning up He remaining in the fore-line piping. The fore-line piping has an open-close valve 10 having a throttle function for introducing the clean up gas.
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