MassGain values in Tuning files

[kst1]

HI! What do MassGain values signify? When I run an autotune on my MSD 5973, I see this value change from one day to another. So, curious as to what it means and is this something to keep an eye on. Thanks!

[GC_Man]

Hello !
The value of the mass gain in your tuning reports is simply the slope of the mass axis.
The quadrupole is measuring the real masses of the tuning substance (PFTBA) and then drawing the curve against the theoretical masses.
This is called mass axis. During the tuning the voltages of the quadrupole are set in a way, that measured masses and theoretical masses correlate in the best way. So the mass gain (slope) and mass offset (intercept) of the mass axis change a little bit between the tunes. This should be normal and you don't have to worry !