Excessive Noise Or Low Signal-To-Noise Ratio - HP 5973 MSD Hardware Manual

 Troubleshooting
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Excessive noise or low signal-to-noise ratio

Possible Cause
The GC injection port needs maintenance.
Action
Refer to the HP 6890 GC manual.
Possible Cause The CI ion source is dirty.
Action
Clean the ion source. See the Maintenance chapter in this manual for more
information.
Possible Cause
Poor vacuum
Action Check the pressure on the high vacuum gauge controller.
Possible Cause Air leak.
Action
Run Methane Pre-tune (in PCI). Large peak at m/z 32 indicates air in the system.
Check for and correct any leaks. See the Leaks section at the beginning of this
chapter.
Possible Cause
Saturated methane / isobutane gas purifier.
Action Replace the gas purifier.
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