在鉴定某工厂试制的、口径为500毫米的油扩散泵时,测得泵的抽速为4580升/秒,最高真空为8×10~(-6)毫米汞柱(功率为3000瓦)。同时发现装在泵上的测量罩较热。 一般认为,油扩散泵的抽速应为泵口径(厘米)平方的三倍,而且大型泵的抽速应高于这个指标。据此,上述500毫米口径扩散泵的抽速应不小于7500升/秒。泵的最高真空,在不加水冷或液体氮冷却的情况下,国外水平约为5×10~(-7)毫米汞柱。 Pumping speed of 4580 liters / sec. And maximum vacuum of 8 x 10-6 mm Hg (3000 watts of power) were tested at a factory-made 500-caliber oil diffusion pump. At the same time, it is found that the measuring hood mounted on the pump is hotter. Generally believed that the oil diffusion pump pumping speed should be three times the pump diameter (cm) squared, and the pumping speed of large pumps should be higher than this indicator. Accordingly, the above-mentioned 500 mm diameter diffusion pump pumping speed should not be less than 7500 liters / sec. The highest vacuum pump, without water cooling or liquid nitrogen cooling case, the foreign level of about 5 × 10 -7 mm Hg.