Shimadzu GC-2014, Instruction Manual

Page: 120 / 318

9 Monitoring the GC
9.4
9
.
108
GC-2014
9.4
Zero Point Adjustment
Zero point adjustment should be executed when the baseline is off-scale. If the baseline cannot
be seen on the screen, execute zero point adjustment so that the baseline returns to the zero
point. The baseline level can also be manually adjusted.
9.4.1
Screen description
Press [Zero Adj] or [Zero Free] (PF menu) from the [Monit] key main screen, the chromatogram
displayed on the monitor screen changes as shown in Fig. 9.4.1 or Fig. 9.4.2.
Press [Up] or [Down] (PF menu) to adjust the baseline level manually.
Zero point adjustments are effective not only for the GC monitor screen, but also a con-
nected pc or Chromatopac. However, zero point adjustments made on the Chromatopac do
not adjust the monitor screen baseline level.
Zero point adjustments are only valid for the currently displayed detector. To adjusts the zero point for
another detector, first switch to its display by pressing [Chng Line] (PF menu), then execute the adjust-
ment.
For the TCD, press [Zero Free] first, turn the TCD zero point rough adjuster on the right side of the unit
to set the baseline close to 0
μ
V, and then press [Zero Adj].
Fig. 9.4.1 Zero point adjustment Fig. 9.4.2 Zero free adjustment
Since the [Down] has been held down too long,
the zero point has deviated into the negative zone.
[Down]
(Held down)
[Up]
(Held down)
[Zero Adj]
[Zero Adj]
[Zero Free]
NOTE