Originally Posted by
ger21
I'm not sure I'm following you, as 29.92inHg is considered a perfect vacuum. I guess that's relative?
What's the formula to convert relative vacuum to absolute vacuum? Do you add or subtract 29.92?
I think your 100mBar (3inHg) absolute is equal to 27inHg relative? If I cover the inlet port on one of my pumps, it too can pull that high very quickly. But trying to evacuate a large canister, or bag, is another story.
I don't think anyone doing vacuum forming or vacuum laminating is using much more than 27-28inHg, as it's not practical.