Chromatography Forum

Hi everyone,

I have a thermofinigan/ Polaris Q GC-MS. Recently I noticed the spectrum became terribly low sensentivity. I ran the diagnostics, it passed almost all the tests, other than the RF gain calibration. The RF calibration should show 3 linearly ramping lines. In my instrument, only the target RF line is ramping, the other two are dead flat.
we have cleaned the ion volume, the ion source lens, replaced the injection septum. Did not help.

This problem happend suddenly, not gradually. Anyone have any thoughts? Thank you so much.

You are most likely looking at a faulty RF generator.. If you are lucky it is just the fuse on the generator it self that is blown..

It could also be one of the power supplies delivering voltage to the RF generator but this is less common.

Good luck!

Thanks a lot for replying. I will try to locate the fuse and see if it is blown. Do you know where can I locate the fuse?

Best regards

we have checked the RF generator fuses and they are fine. Any other suggestions? Thanks a lot.

It can also be the RF generator itself that is dead..

If you have the guts to try it you can check a second fuse on one of the powersupplies that supply voltage to the RF Generator.. It is located somewhere at the bottom of the Power module.