Agilent Technologies 7500 ICP-MS Operator's Manual page 164

Agilent 7500 ICP-MS ChemStation Operator's Manual
Tuning
The window includes three boxes. Each box is 3 AMU wide and shows the peak
shape for one mass.
4 Click Start to monitor the Agilent 7500 signals and view the spectra and
numerical values in the real-time display.
Three spectra will be displayed one in each box. The spectra are obtained by 20
points per mass, three masses per window, for 100 scans. To adjust the resolution
and mass calibration in a wide range of mass scale, three masses should be selected
from lighter mass to heavier mass, 0.1 or 0.05 seconds integration time is appropri-
ate. Using the standard tuning solution,
ChemStation inserts numerical values for the following items when the real-time
display starts:
• Height
Shows intensity of the peak top in each box.
• Axis
Shows mass axis of the peak top in each box. Mass axis should be within ± 0.05
of the selected mass.
• W-50%
Shows peak width (AMU) at 50 percent of the peak height.
• W-10%
Shows peak width (AMU) at 10 percent of the peak height. W-10% should be
0.65-0.8 AMU.
5 Adjust the following parameters manually if necessary.
Click each text box and use the arrows to change the parameter value. Adjust the
tuning parameters until the resolution and mass calibration are within targeted value.
• AMU Gain
Adjusts peak width. The higher the value, narrower peak widths for heavier
masses.
• AMU Offset
Adjusts peak width. The higher the value, narrower peak widths for all masses.
• Axis Gain
Adjusts mass calibration. The higher the value, shifts the peak position of heavier
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Li, Y, and Tl.