Talk:Cryopump

Latest comment: 8 years ago by 146.186.247.120 in topic Pressure unit

Picture

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We're going to need a picture for this if wikipedia is ever going to amount to anything. —The preceding unsigned comment was added by 207.157.65.2 (talk) 20:18, 13 March 2007 (UTC).Reply

Gases vs. Vapors

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The comment about "high boiling point gases such as water and oil" needs rewritten. Both water and oil are vapors, not gases. But are there also high boiling point *gases* which are pumped by the warmer stage? What temperature is this warmer stage at, ~60 K ???

What is the difference between a cryopump and a cold head (or coldhead)? Is the cold head that part of the cryopump which gets the coldest?

As for pictures, would someone at Brooks CTI and/or Oxford/Austin provide one? I read the Wikipedia copyright restrictions as prohibiting me from pasting an image from a commercial website (free advertising!), else I would have posted one. Tom10001 (talk)

Pressure unit

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Why is Torr used here? Is there a particular reason? I would tend to prefer the SI unit EAR47 (talk) 23:00, 12 July 2016 (UTC)Reply

@EAR47, The Torr (mm of Hg) is the common unit for vacuum gauges in the USA. Going by vendor literature, most or all other countries use the bar and millibar for this purpose. The longer answer is that in the USA many mechanical gauges (Bourdon tubes) display in "inches of Hg vacuum" as well as in kiloPascals of vacuum. Digital readouts can be set to display in either Torr or bar/millibar. Some units will display in microns ("micrometers of Hg" which is the same as milliTorr). While the bar and millibar are not SI standard units, you just move the decimal place on Pascals to get bars. Some papers require you to convert your Torr and bar values to Pascals for publications and others do not. --Tom — Preceding unsigned comment added by 146.186.247.120 (talk) 23:27, 12 July 2016 (UTC)Reply