Agilent Technologies 7000 Triple Quadrupole GC/MS, Руководство по обслуживанию

Страница: 157 / 214

Analyzers and Collision Cell
7
Troubleshooting and Maintenance Manual 157
Width gain
Width gain affects the ratio of DC voltage to RF frequency on the mass filter.
This controls the widths of the mass peaks.
• Higher gain yields narrower peaks.
• Width gain affects peaks at high masses more than peaks at low masses.
Width offset
Width offset also affects the ratio of DC voltage to RF frequency on the mass
filter.
• Higher offset yields narrower peaks.
• Width offset generally affects peak widths equally at all masses.
Mass gain
Mass gain controls the mass assignment, that is, assignment of a particular
peak to the correct
m/z value.
• A higher gain yields higher mass assignment.
•
Mass gain affects peaks at high masses more than peaks at low masses.
Figure 30 Quadrupole mass filter
C A U T I O N
Using the nonpreferred DC polarity may result in very poor performance. Always use
the factory-specified polarity.