Sciencemadness Discussion Board

Manometer issues

nimbus8 - 5-8-2013 at 14:54

Hey everyone i have a vaccum setup with a digital manometer and a controlled leak valve. The issue is that when i close the leak valve there should be more vacuum being pulled. But the manometer reads differently. As the valve is closed the manometer will go from reading 7.8 torr to 14 torr. Now im not sure which one is the positive and the negative terminal on my manometer but ive tried both and neither work.

ElectroWin - 5-8-2013 at 15:03

is there something in there with a vapour pressure of ~14 torr?

nimbus8 - 5-8-2013 at 15:08

No, im using it on glassware with nothing in it.

vmelkon - 8-8-2013 at 18:00

Maybe write what the model and make is.

My guess : It could be a flow manometer. In other words, there needs to be a flow of gas. That's good for pressure lines, where you have some gas flow.