The Fore vacuum of my MS is showing a high value.
- GCMS ISQ
- GCMS TSQ
- Check all parts or components you could have manipulated before.
- Check noise level of the pump, check oil level and if oil is not leaking from the pump.
- Check vacuum tubing and hose clamp.
- Check if the vent valve knob is tightened.
- Tighten the transfer line nut, check / replace columns ferrules.
- Clean the glass top cover O-ring.
- Check/clean front door o-ring if it was opened.
- Check the helium pressure/flow applied in the column.
- Check the argon applied pressure.
- Check the CI gas is turned off if CI module is present.
- Check if the issue is coming from MS or GC: Shutdown down the MS, remove the column from the transfer line and put a plug instead. Argon or air spray gas can be used around the vacuum manifold to look for characteristic ions (40-100).