Varian 4000ms and RF issues

[Letuter]

Hi Guys,

In my wisdom I decided to do some maintenance on my mass spec.

I took apart the trap and cleaned it, I put it back together with no issues.

But when I started it back up, the system verification told me that the RF wasnt working. When I went to the RF ramp adjustment, the display was bouncing around everywhere with no stable ramp at all.

I have reinspected the trap, there are no gaps, the quartz rings are intact, the oven seems to be making good contact with the manifold, the electrodes are in correctly, the probes inside the vacuum chamber look good. What have I done wrong?? Is there anything else I could look at???

Help!!!!

[Letuter]

good news....its all fixed.

In my original post I forgot to mention that I changed two of the quartz spacers as one was slightly chipped.
This in turn sent the RF loopy.
As Im used to operating the Saturn 2000 rather than the 4000 I never turned the RF adjustment screw enough, when I was informed to try adjusting the screw from end to end (many many many turns) it fell in nicely. Aparently the variance between the 2000 and the 4000 is purely down to the 4000 being much more senstive.

Thanks for all your help guys.

[akthmps]

I'm curious to know your thoughts on the Saturn 4000 vs. the Saturn 2000. I've always been happy with Varian GC-MS, much more so than Agilent GC-MS.

Any comments on this new system would be appreciated.

Thanks,
Aaron

[Letuter]

The more I learn about the 4000 the more I am impressed with it. It has great flexibility with options between external, internal or hybrid ionisation, and they can be switched between the different modes relatively easily (we only use internal mode here). The sensitivity is excellent in just the ms scan mode not (not ms/ms or sis), with our lab being able to achieve the same detection limits as our sister labs (who use Agilent) with less sample. Maintenance is minimal, we have had this instrument just over a year, and Ive only just thought it was time for a clean, and apart from the RF incident, it was very easy. All in all, I find the 4000 more flexible, more sensitive and easier to use than the 2000.