Sauron - 7-3-2007 at 06:37
The attached pdf contains two articles setailing construction of simple low cost vacuum gauges, one based on thermocouple and the other on a
thermistor.
These operate in the range of 0.001 torr to 1 torr or higher, that is, at ranges where most manometers and McLeod gauges are pretty useless. This is
"medium vacuum" country whereas where most chemists live is regarded as low vacuum (>1 torr). High vacuum is the relatively exotic realm of
<0.001 torr down to 0.0000001 torr which can only be reached with auxiliary pumps (diffusion, cryo, turbomolecular, etc.)
[Edited on 7-3-2007 by Sauron]
Attachment: http___www.belljar.net_tcgauge.pdf (185kB)
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