Used either solely as Rough Pumps, or in combination with other high vacuum pumps as Backing Pumps.

可单独作低真空泵用，也可与其他高真空泵组合作前级泵用；

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The rules of the last balance position is illuminated, and also the way how does the characteristic curve of the vacuum booster reflect the backing velocity of it is presented.

同时，给出了真空助力器的特征曲线是如何反映助力器回程速度的方法。

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Rotary piston pumps always used as backing pumps of vacuum systems in vacuum induction ovens.

真空感应炉真空机组中的前级泵，历来使用滑阀泵。

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