Waters/Micromass Q-TOF API typical pressure?
Posted: Wed Mar 07, 2018 11:07 pm
by gapeev
Hello!
What would be typical/normal "backing pirani" pressure for this instrument?
It's showing around 1 mBar and I suspect there is a leak in the forevacuum line. All turbos spin at 100%
Thanks!
Re: Waters/Micromass Q-TOF API typical pressure?
Posted: Thu Mar 08, 2018 3:51 pm
by Gaetan Glauser
I don't know what the pressure is on this instrument, however I am sure it should be well below 1 mbar (maybe 10-5 - 10-7 mbar). This anormaly high value might be due to two distinct things:
1) the vacuum inside the MS is good but the gauge sucks.
2) the vacuum is really at 1 mbar for some reason.
If your pumps are working 100%, I would strongly suspect the gauge. To know if this is the case or not, just run a known sample. If you have similar results as before, the problem is the gauge, and if you don't detect any ion, the vacuum is really 1 mbar. We are currently running a triple quad from Waters which displays a supposed pressure of 1.4 mbar but otherwise works perfectly.