I'm struggling maintaining a stable vacuum in a new schlenk line I built and was hoping to get tips. My background is in materials science so my experience with chemistry labs is limited.
Currently I'm only able to a get the vacuum down to 200 mTorr but as soon as I close the valve to the pump, pressure goes up pretty quickly to a few torr and then the leak stabilizes to 1 torr/minute. I have worm clamps at the tubing connection points and have tried both gum rubber and braided tubing. I also tried different vacuum pumps, tried switching where the connections are and I removed the cold trap flasks but the results are still the same. I'm not sure what else I can try or where exactly i'm going wrong.