After changing the O2/H2O scrubber on our 5977/8890 we experienced a large increase in noise/column bleed. I did check the air/water levels about an hour after the scrubber change, and the levels were ~3% for water and nitrogen.
After running a blank sample the baseline noise increased by more than 60-fold. No other changes to the instrument or method were made. I know the scrubbers are packed under nitrogen, but I thought it had mostly moved through the system.
Since then I worked with our FSE on cleaning the HED and source. I have tuned and retuned several times. I restored the ATune and BFB files from the 5977.old folder without any improvement in noise/bleed.
This system is used for TO-15 analysis and has a preconcentrator attached for CTD.