Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 114)

<1. Overview>
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IM 11B08A01-01E
The setting range is shown below.
Tracking factor a 0.500 to 2.000
Tracking factor b -21600.000 to +21600.0
If auto-calculation result of tracking factor a/b does not fall within the above scope, the level 3
alarm, “#484 Peak tracking failure” occurs, and automatic renewal of tracking factor a/b and
tracking of gate ON/OFF time and base level processing operation time are not performed.
 Tracking standard and tracking interval at automatic renewal of tracking
factors
When “Update” is set for “Automatic renewal of tracking factors” of SYS method, calculation
is performed by “Peak standard time“ of the peak for which “Standard” is set for “Tracking
specifi cation“ in peak individual setting, and “Retention time“ of the measurement result. When
multiple detections are set in SYS setting, tracking factor a/b is calculated per detector.
Determine “Tracking interval” according to the number of peaks, which were set for “Standard,”
and alignment, and automatic renewal the tracking factor a/b. Determine Tracking interval
according to the number of peaks for which Standard is set for “Tracking specifi cation” of peak
individual setting, and alignment, and automatic renewal the tracking factor a/b. Calculation
method is different when “Standard” is one and when it is more than one.
The rules of tracking standard and tracking interval are explained below. The peak which was set
as “Tracking execution” and the peak which was set as “Standard” are called “Tracking peak” and
“Standard peak,” respectively.
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• The fi rst tracking peak follows the subsequent standard peak.
• The fi rst standard peak is calculated by a single standard peak (itself).
a1 = y1 / x1
b1 = 0
• The tracking peak that exists between the 1st standard peak and the 2nd standard peak
follows the 2nd standard peak.
• The 2nd standard peak is calculated by two standard peaks of the 1st and the 2nd.
a2 = (y1-y2) / (x1-x2)
b2 = y1 - {(y1 - y2) / (x1 - x2)} × x1
• The tracking peak that exists between the 2nd standard peak and the 3rd standard peak
follows the 3rd standard peak.
• The 3rd standard peak is calculated by two standard peaks of the 2nd and the 3rd.
a3 = (y2-y3) / (x2-x3)
b3 = y2 - {(y2 – y3) / (x2 – x3)} × x2
• The peak that exists behind the 3rd standard peak with no subsequent standard peak
follows the 3rd standard peak.
• When multiple detections are set in SYS setting, tracking factor a/b is calculated per
detector.
• “The 1st, 2nd, 3rd......” stands for the order from the earliest retention time, not the numerical
order of the peak number.
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x: Peak standard time, which was set for tracking criteria
x: Peak retention time, which was set for tracking criteria
a: Tracking factor (Inclination)
b: Tracking factor (Intercept)
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2nd Edition : May 11, 2012-00
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