Pumping pressure question - English vs. metric

Hello to all,

I know this question should be posted in the ‘pumpers’ section, but as a new member I don’t have permission to post in that section.

When reading about pumping pressure in the forums, it is advised to pump at a vacuum pressure between
3 Hg and 6 Hg.
Remembering my physics lessons at school I realize that this relates to the height of a mercury column in a vertical tube. So in this case between 3 inch and 6 inch of mercury column.
(I believe it is called “The tube of Toricelli”)

The problem I have is that I live in Europe and we use Metric sizes.
I don’t have a gauge yet but I suppose when ordering one, the reading would be BAR, Kpa or Kg/cm2 ?

Can somebody please convert 3 and 5 Hg figures to metric?

Thanks,
Alex

No problem, Handige. I moved it to the Pumpers Forum for you.

The gauges I’ve seen have both inHg and mmHg on it, and the standard inches to mm conversion applies. Thus, one inHG is 25.4 mmHg.

Three inHg would translate to a bit more than 75 mmHg.
Four inHg would translate to a bit more than 100 mmHg.
Five inHg would translate to a bit more than 125 mmHg.
Six inHg would translate to a bit more than 150 mmHg.

Hi dude, im not sure but 0.2 BAR 100xkPa = 6 Hg.

Josh.