出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/06/06 17:31 UTC 版)
A roughing pump is any vacuum pump (typically mechanical) used to initially evacuate a vacuum system, as a first stage towards achieving high vacuum or ultra high vacuum. The term "roughing pump" derives from the vacuum range it works in, "rough vacuum", above 1x10-3 torr. Pumps that operate in the high vacuum ranges typically don't operate or operate inefficiently at atmospheric pressures, whereas pumps that work efficiently at atmospheric pressure usually can't produce a vacuum lower than approximately 1x10-3 torr.