Thermo Scientific TSQ Altis, Hardware Manual

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15
Calibrating the MS
Calibrating and Tuning the MS
Thermo Scientific TSQ Altis, Quantis, and Fortis Hardware Manual 63
Mass Calibration
Use the Mass Calibration option ( Figure 28 ) if the Check Mass Calibration option fails.
During the mass position and resolution evaluation, the calibration procedure varies the RF
and DC voltages that it applies to quadrupoles Q1 and Q3 to best fit the measured peak
widths and positions of the EMRS calibrant ions. This procedure repeats for FWHM peak
widths of 0.2 Da (TSQ Altis MS only), 0.4 Da, and 0.7 Da; for three different scan rates
(250, 500, and 1000 Da/sec); and for quadrupoles Q1 and Q3.
EM Gain Calibration
If you notice a falloff of the ion signal intensity, use the EM Gain Calibration option
(
Figure 28 ) to increases the voltage on the electron multiplier. This will maintain a gain of
1 × 10
5
for MS mode and 1 × 10
6
for MS/MS mode.
Tune and Mass Calibration
When you select the Tune and Mass Calibration option ( Figure 28 ), the MS maximizes the
ion signal by optimizing the DC offset voltages of the lenses and other optical elements.
Figure 31 shows the lens L0 offset voltage optimization for EMRS. After the optimizations are
complete, the system performs a full mass position and resolution calibration.
Figure 31. Ion signal intensity as a function of the lens L0 offset voltage