I got a degasser (Shimadzu DGU-14A) which seems to work, but I do not know if it works properly or not. It makes all correct noises, turns the vcuum pump on and off, lits correct LEDs, does not leak, but there are still bubbles in the mobile phase coming out of it now and then. Should I just give it more time to "stabilize"? Is observing bubbles on the out line the only way to check if it is operating properly? I can watch flowing mobile phase for a while, but I am not sure for how long I last before falling asleep :-).