HED Supply Difficulty

[espx_2]

This is actually really crazy because we're having that same problem but on a different 5975. Unfortunately we haven't fixed it yet. I tried cleaning the HED but that didn't seem to do anything. I've never really come across this problem before so troubleshooting it is a little tricky. At first I thought there might be some metal touching metal but I couldn't see any discrepancies in the detector. There didn't appear to be any dust anywhere either. I can't believe we're still having the same problems as each other...

Yeah! I believe so... By the way, our air components abundances were reducing gradually. But still, I'm having a lot of peaks across the scan from 10 to 700 m/z. Have you try to check the pressure inside the ion source chamber?

Thanks.

What do you have the threshold set to in your tune? Normally it is run about 50-100 counts. If you have the threshold set to 0-10 counts you could easily get those 800 peaks across the scan. The lowest I have ever been able to run my threshold was 10 and that was after it had been running for a week and I had reduced the multiplier voltage as low as I could without loosing sensitivity.

James,

I'll be checking on regarding the threshold set on the GC-MS. Later, I'll power on the MS because it was turned off (as instructed by the service engineers). I'll get back to you on this...

Thanks.

[espx_2]

Guys!

We've fixed the problem!!! The only thing we did was to clean the EM Horn and replaced the vent valve and calibration valve o-rings. I noticed it because once I ran tunes using PFTBA, the water and air components increases overtime.

Thanks for helping me out.