PerkinElmer FLEXAR SQ 300 MS, Руководство пользователя

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112 .
Flexar SQ 300 MS User’s Guide
3. Enter shortest Baseline Segment Size , and Baseline Noise Window .
NOTE: An increased Baseline segment value will flatten the baseline. A decreased value may lead to a baseline
which interferes with the peaks.
The level of the calculated baseline is found in the Peak Information box when Manual peak
detection is used.
4. Select
Manual
to create a
Manual
baseline by entering a value resulting in a straight line as a
baseline.
5. The baseline can be hidden or displayed with the
Baseline
from the
View
menu.
6. The baseline can be subtracted from the chromatogram by selecting Subtract Baseline from the
Evaluation menu.
Setting Spectrum Noise Calculation Preferences
To set mass spectrum noise calculation preferences:
1. When a mass spectrum window is activated, select Noise from the Evaluation menu.
2. To detect the noise manually, select
Manual
and enter a mass range where there are not any peaks.
3. Select a
Function
:
Peak to peak
or
Root mean square
.
4. In the default version of the signal to noise calculation the following is done:
• If the noise is Peak to peak then the amplitude of the peak top or the centroid is subtracted
by the low value of the noise and divided by the peak-to-peak difference.
•
If the noise is Root mean square then the amplitude of the peak top or the centroid is
subtracted by the mean of the noise and divided by six times the standard deviation of the noise.
5. Click
OK
.
6. The level of the calculated noise is found in the Peak Information box when Manual peak detection
is used.