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General Troubleshooting
2
Troubleshooting and Maintenance Manual
35
High background
•
Pressure in the analyzer chamber is too high
•
Air leak
•
Contamination
Mass assignments are incorrect (scan mode only)
Small shape changes at the top of the mass peaks can cause 0.1
m/z
shifts in
mass assignments. Shifts greater than 0.2
m/z
indicate a possible malfunction.
•
MS has not had enough time to reach thermal equilibrium
•
Large variations in the temperature of the laboratory
•
MS has not been tuned recently or at the temperature at which it is
operating
•
Incorrect tune file (inappropriate parameters)
•
No voltage to extractor lens (if using extractor EI source)
Peaks have precursors
The tune report lists the size of the precursors for the tune masses. Small
precursors are not unusual. If the precursors are unacceptably large for your
application, one of the following may be responsible:
•
Repeller voltage is too high
•
Peaks are too wide
•
Incorrect DC polarity on the quadrupole mass filter
•
Dirty quadrupole mass filter
Peak widths are very low
•
MS has not had enough time to reach thermal equilibrium
•
Large variations in the temperature of the laboratory
•
Incorrect tuning
•
Calibration vial(s) empty or almost empty
•
Calibration valve(s) not working correctly
•
Dirty ion source
Содержание 7000 Triple Quadrupole GC/MS
Страница 24: ...24 Troubleshooting and Maintenance Manual 1 Introduction...
Страница 50: ...50 Troubleshooting and Maintenance Manual 2 General Troubleshooting...
Страница 122: ...122 Troubleshooting and Maintenance Manual 4 General Maintenance...
Страница 144: ...144 Troubleshooting and Maintenance Manual 6 Vacuum System...
Страница 182: ...182 Troubleshooting and Maintenance Manual 8 Electronics...
Страница 193: ...Replacement Parts 9 Troubleshooting and Maintenance Manual 193 Figure 45 Foreline pump top and safety cage parts 1 6 5 7...
Страница 212: ...212 Troubleshooting and Maintenance Manual 9 Replacement Parts Figure 50 CI flow control module 5 3 4 2 1...
Страница 213: ......
Страница 214: ...Agilent Technologies Agilent Technologies Inc Printed in USA September 2009...