Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 482)

<Appendix E Computation Scheme>
App.E-9
IM 11B08A01-01E
For instance, assuming the assigned number of peaks is 5 in the zone peak detection starting at
peak 3, the peak detection is started from the gate on, and if the detection is performed normally,
the data will be stored in the peak buffers of peak 3, 4, 5, 6, and 7 in the order of detection.
(ii) Generation of peak search errors
If the gate is fi nished after the peak detection has been started but before the peak detection
of the assigned number of peaks is not completed, peak search errors with regard to the
undetermined peaks will be generated. In the same example as above, assuming that three
peaks are detected before the gate off, peak search errors will be generated for peaks 6 and 7,
respectively
(iii) Coexistence of zone gating with other peak detection actions
Like the slope gating, time gating and slope-on/time-off method, the zone gating method is
performed by setting at the peak unit. Therefore, the zone gating method is considered as one of
the regular detection actions, allowing it to coexist with other detection methods in one stream.
(iv) An action when the previous peak is on before the zone gating starts
If the previous peak (in this case, the slope detection peak) has not been fi nished before the zone
gating starts, the previous peak is forced to become off at the time the zone gating turns on. At
this time an error message or any other notice indicating the forced termination is not generated.
(v) An action when the current peak is on upon the zone gating is fi nished
If the currently detected peak is not fi nished when the zone gating processing is fi nished, the
current peak is forced to become off at the time the zone gating turns off. At this time an error
message or any other notice indicating the forced termination is not generated.
(vi) Auto-tracking peak method in the zone gating
In the auto-tracking peak in the zone gating method, specifying the tracking standard is not
supported. Therefore, either “Tracking exec” or “No tracking” should be specifi ed for the peak
tracking in the zone gating. When “Tracking exec” is specifi ed, the setting of a starting peak in the
zone gating becomes effective and the second and the following settings are disregarded.
(vii) Confi rmation of minimum detection height/area
In the zone gating method, the settings of minimum detection peak height and area are enabled
and for the peaks detected in all zone gating processing, the minimum detection peak height
and area are checked uniformly. If there are some peaks not satisfying these conditions, the
processing and data storing of those peaks are skipped and the following peak is processed.
This means that the peaks not satisfying these conditions are not counted as a zone assigned
peak, but discarded.
(viii) Setting of the peak detection conditions
The zone gating method performs slope detections under the same conditions by using the
setting of the starting peak number (slope conditions and polarity) in the zone gating with regard
to the slope detection conditions of the peak in the zone.
(ix) Handling of chromatograph data errors
If void data are found in the detecting peaks, the zone gating method generates a chromatograph
data error, skip processing and data storing of the peaks of concern, and performs the following
peak processing. Peaks that have caused a chromatograph error will not be counted as a zone
assigned peak, but discarded.
(f) Slope/Time Method
Unlike the usual slope detection method or time gating method, slope/time method performs a
peak detection by using the slope detection method for the peak on detection and the time gating
method for the peak off.
2nd Edition : May 11, 2012-00
App.E