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Transpector XPR 3+ Operating Manual
7.6  Mass Calibration
7.6.1  Mass Alignment
Transpector XPR 3+ is tuned such that it generates a known RF/DC ratio that 
allows one mass to exit the quadrupole at a time. When tuning the mass scale of 
Transpector XPR 3+, the RF/DC ratio is fine tuned to each tune mass. 
Another part of preventive maintenance is checking the functional operation of 
Transpector XPR 3+. This includes the mass position and mass resolution of the 
instrument. While this mass scale tuning is accomplished in a similar fashion to 
any other Transpector, Transpector XPR 3+ does have some slightly different 
values for peak width adjustment.
For more detailed information reagrding mass tuning using FabGuard, please refer 
to the FabGuard Explorer operating manual
7.6.1.1  Factory Tuning
The gases that are used for factory tuning of these masses are:
 Hydrogen (mass 1 and 2)
 Helium (mass 4)
 Nitrogen (mass 28)
 Argon (mass 40)
 Krypton (mass 86)
7.6.1.2  Mass Scale Tuning at Base Pressure
Mass scale tuning can be done at base pressure using the background peaks of 
water vapor (18 AMU) and nitrogen (28 AMU). The following procedure should be 
used to check peak location and peak widths at mass 18 and mass 28 and to make 
adjustments as needed.
Do not attempt to remove masses 1, 2, 4, or 86 AMU from 
the Tune Table or adjust the resolution at these masses.