BG 805 201 BE (9911) QMS200.om
27
u
Repeatedly measure the spectrum of the peak groups that are of interest
because in this optimization not only the intensity but also the resolution and
the peak shape are important. Standard parameters are:
SPEED:
1s/u
MODE:
SCAN-N
RESOL:
50
RANGE:
10
-9
or AUTO
IonRef:
150 V / Cathode: 90 V
v
Adjust the Extraction and Focus voltages to max. peak height in the
following order:
EXTRACT: 6 ... 30 V
FOCUS:
typically 6 ... 10 V
Set FIELD AXIS as follows:
1. Set to 8 V.
2. Reduce the voltage so that the peak intensity drops to about 1% of the
original value.
3. Increase the voltage by 3 V.
4. If the peak structure is too pronounced, reduce the voltage accordingly.
The ion source is now optimized.
x
When working with a new ion source repeat
v
after several hours of
operation.
y
Quit the "Ion source" window and save the data.
If the QME or QMA needs to be replaced, the procedure is the same as for the
initial installation.
The individual steps are:
1. Installing the QME
→
16
2. Connecting the QME
→
16
3. “TUNE” of RF generator
→
26
4. Optimizing the ion source
→
26
5.2.5 Replacing the QME
Summary of Contents for Prisma QMS 200
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