I am using two old fashioned pumps (the ones that have the belts which spin with the motor) hooked in 'series' (like resistors sometimes are in an electric circuit). How low do you think this will be able to pump?
Is it better to hook them 'parallel'?
There is a gauge on the pump right before the chamber which measures from 10 to 100 kPa and 0 to 30 in. Hg vac. I have found that the numbers get HIGHER as the pump is turned on longer. How exactly does one read such a gauge (i.e. what would 1 torr be on the gauge)?
Also, do you know how acurate these gauges that come with pumps are?
I am using a bell-jar system with a plastic base. For electric leads, I drilled holes into the base and used circular glass rods ~0.25" wide with a 0.03" opening with wire through. I then melted the glass to seal it and placed it through the opening, expoxied, vacuum greased, etc. How good of a vacuum is this?
Created on Wednesday, February 21, 2001 8:07 PM EDT by - unknown -