My tune reports on my GC 6890N/5973 MSD have been really noisy/low sensitivity. My source is clean and I don't know what else it could be. Leak maybe?

Look at your air/water check. You have a huge leak.

Thank you for the response. That number has drastically gone down so there's no leak. Any other suggestions? 

Hello xio,

the case is a bit older: do the problems still exist?

If so, a new tune report would be more than helpful.

small hint to the first tune report (24th July):
a) If the H20 value is too high (e.g. like in the first 1-2h after pump down: the H20 value is gigantic) then usually the N2/O2 is also very high, WITHOUT a leak!
Therefore: if the H2O value is higher than 5-10%, first look for the cause of the water reason.

Pump down: after one night the H2O value is usually less than 3(-5)% if the MSD is supplied with column flow.
If the MSD is NOT supplied with carrier gas (blind sealed) the MSD needs much longer to pump down the H2O from the MSD; here I have seen several days higher H2O values.

b) Number of peaks=512
this value is also MUCH too high.

it could also drop to a normal level 100-150 peaks if the H2O value is at a normal level

regards, M.

Hi,

“I just wanted to follow-up to see if your issue has been resolved. If you still need help, just let us know and we would be happy to continue working with you.”

Hi

Change helium cylinder..sometime helium impurity give such error.

Check all filters connected with helium line,if very old then change those filters..

After that if problem continue then you can perform bakeout of MS then next day do autotune to see result...