Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 180)

<3. Basic Operation and Startup>
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IM 11B08A01-01E
11/03/22
15:15:45
Peak Setup-General
GCM #1
> - Conc calc req
Standard
- Det slope ratio 1.00
- Calib range 0.500
- Calib repeat range 2.000
- Calib coef range 4.000
- #1 Tickmark setup None
- #2 Tickmark setup None
- Peak detect err set
Executed
Menu Gate Valve Atm DO GCM#
F1 F2 F3 F4 F5 F6
Figure 3.24 Example of Common peak setting screen
 The method of changing the Reference area
Setting the Calibration factor range to 0 changes the Calibration factor in the Individual peak
setting (Figure 3.23) to 1 after the calibration and also changes the Reference area to the
value obtained by calculation. In this method, values are changed regardless of the value of
the Reference area obtained, so the automatic calibration fi nishes normally and the calibration
value is updated even if the measurement result of the standard sample is abnormal. Therefore,
from the set values of the Calibration range and the Calibration repetition range, decide by the
following method if the calibration result should be refl ected.
When the Calibration range has been set to α and the measurement result of the standard
sample is out of the Reference concentration ± the Measuring range × α, an alarm message
appears and the calibration result is not refl ected.
When the Calibration repetition range has been set to α and the variation coeffi cient obtained
from n times of measurement results of the standard sample is larger than α, an alarm message
appears and the calibration result is not refl ected. A variation coeffi cient is a value obtained by
the division of a standard deviation by a measuring range. For the equation, see the Appendix E
Calculation.
This method is not suitable for the history management of calibration. A method of changing the
Calibration factor, described below, is recommended to normal calibration.
At the factory, calibration has been conducted according to the method of changing the
Reference area.
 The method of changing the Calibration factor
Setting the Calibration factor range to other than 0 does not change the Reference area in the
Individual peak setting after the calibration (Figure 3.23) but changes the Calibration factor to the
value obtained by calculation.
In this method, decide by the following method if the calibration result should be refl ected from
the Calibration factor. At the same time, use the Calibration range and the Calibration repetition
range.
When the Calibration factor range is set to α and the obtained Calibration factor is between 1
– α and 1 + α, the calibration result is refl ected. If the obtained Calibration factor is smaller than
1 – α or larger than 1 + α, an alarm message appears and the calibration result is not refl ected.
For example, when the Calibration factor range is set to 0.1 and the obtained Calibration factor is
between 0.9 and 1.1, the calibration result is refl ected.
2nd Edition : May 11, 2012-00
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