78
3
Troubleshooting the MSD
Mass spectral symptoms
High mass sensitivity is poor
This refers to a condition where the
absolute
abundance at the upper end of the
mass range is poor. Absolute abundance should not be confused with the
relative
abundance (percentage) of
m/z
502 to
m/z
69. Sensitivity at high masses can be
excellent even if the relative abundance of
m/z
502 is low.
•
Wrong tune program
•
Wrong tune file
•
Repeller voltage is too low
•
Not enough time for the MSD to warm up and pump down
•
Vacuum manifold pressure is too high
•
Column (carrier gas) flow is too high
•
Poor filament operation
•
Dirty ion source
•
Air leak
•
Incorrect dc polarity on the quadrupole mass filter
Summary of Contents for 5973
Page 1: ...H Hardware Manual HP 5973 Mass Selective Detector ...
Page 3: ...HP 5973 Mass Selective Detector Hardware Manual ...
Page 25: ...1 Installing GC Columns To condition a capillary column 25 ...
Page 30: ...30 ...
Page 37: ...2 Operating the MSD To view MSD analyzer temperature and vacuum status 37 ...
Page 39: ...2 Operating the MSD To set monitors for MSD temperature and vacuum status 39 ...
Page 41: ...2 Operating the MSD To set the MSD analyzer temperatures 41 ...
Page 43: ...2 Operating the MSD To set the interface temperature from the ChemStation 43 ...
Page 51: ...2 Operating the MSD To remove the MSD covers 51 Upper cover Lower cover ...
Page 92: ...92 ...
Page 105: ...4 Maintaining the MSD To drain the foreline pump 105 Fill cap Drain plug Pump motor ...
Page 113: ...4 Maintaining the MSD To separate the MSD from the GC 113 ...
Page 121: ...4 Maintaining the MSD To reconnect the MSD to the GC 121 ...
Page 141: ...4 Maintaining the MSD To lubricate the side plate O ring 141 Side plate O ring ...
Page 159: ...4 Maintaining the MSD To remove a filament 159 Filament 2 Filament 1 ...
Page 161: ...4 Maintaining the MSD To reinstall a filament 161 Filament 2 Filament 1 ...
Page 210: ...210 ...
Page 214: ...214 ...
Page 232: ...232 7 Analyzer Analyzer heaters and radiators ...
Page 280: ...280 ...
Page 294: ...294 Index ...
Page 296: ...294 Chapter ...
Page 297: ...H Manual Part Number G1099 90027 Copyright 1998 Hewlett Packard Printed in USA 11 98 ...