interpreting mass gain in the tune report

[chromatonewbie]

Hi guys,

I'm looking after a 5973 MSD and I've noticed that the "Mass Gain" on the latest autotune report (after a source clean, a filament replacement and a slight rotation of the electron multiplier) was -29. This is higher than before the source clean, when it was -15. Why would this be? Does it matter?
What range should it be in?

cheers
Liz

[tangaloomaflyer]

Do you mean -29 or +29?

[chromatonewbie]

it says -29