| 摘要 |
PROBLEM TO BE SOLVED: To grasp the impairing of exhaust capability of an ion pump in advance by detecting an ion current of the ion pump and displaying its ion current integrated value. SOLUTION: An operating condition of an ion pump 10 can be quantitatively grasped by knowing an integrated value (Ip×t) of ion current IP and a time (t) during the use of the ion pump 10, and the impairing of the exhaustability of the ion pump 10 can be known when the ion current integrated value It becomes a predetermined value. A converting circuit 5 of an ion pump power source 1 starts the integration of the ion current when receiving a power-on signal of a power source switch 8, the obtained integrated value is added to the accumulated ion current integrated value It, and the obtained integrated value is displayed on a display part 6. By knowing that the integrated value is close to a value indicating the start of the impairing of the exhaustability of the ion pump 10, the exhaustability can be recovered by burning out the ion pump.
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