Galvanic Applied Sciences 943-TGX-CE, Operation Manual

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Revision 4 57 April 2020
Table 11: Spectrometer Parameters
Parameter Explanation
Peak Height
Displays the peak height of the transmission spectrum, in
A/D counts. Should be approximately 28000-29000 when
analyzer is in back purge mode.
First Vector Pixel
Displays the intensity of light being received at the first
vector pixel, in A/D counts. The first vector pixel is the first
pixel that is used for calculating concentration values.
Dark Level
Displays the intensity of light being received when the
spectrometer is dark (i.e. no light present). This value
should be in a range between 400 and 900 A/D counts.
Below the spectrum are two buttons referring to a parameter called Integration Period , the Set
Integ. Time button and the Optimize Integ. Time button. The integration period is the duration
of time that light is collected by the pixels of the spectrometer before being read by the control
computer. For example, in Figure 30 the integration time is given as 123.69 milliseconds. This
means that the light incident on the spectrometer pixels is allowed to accumulate for 123.69
milliseconds before being read by the control computer; the spectrometer pixels are then zeroed
and allowed to collect light again. The displayed transmission spectrum, then, shows the
intensity of light collected at every pixel in this duration of time. The integration time is a
compromise to optimize the resolution while minimizing noise in the spectrum. A short
integration time will optimize the resolution and show fine detail in the spectrum, but the noise
level may be relatively high. Contrarily, a long integration time will reduce noise, but fine detail
in the spectrum may be lost. The integration time has a maximum value of 1000 milliseconds.
The optimal integration time for the current analyzer conditions can be automatically calculated
by pressing the
Optimize Integ. Time button. Use the F4 / F3 keys to highlight this button, then
press
↵
to optimize the integration time. Once pressed, the control computer will adjust the
integration time such that the peak height of the displayed spectrum reads approximately 28000
A/D counts. If this peak height cannot be achieved even with a maximum integration time of
1000 ms, this indicates a problem with the analyzer’s optical system. Refer to section 7.2 for
troubleshooting tips.
Optimizing the Integration Time should ONLY be performed when the analyzer is in
back purge mode. Attempting to optimize the integration time when the analyzer is
in sampling mode may negatively affect the analyzer baseline, and thus the
analyzer’s analytical results.
As an alternative to automatically optimizing the integration period, the operator may choose to
manually adjust the integration period instead. Use the F4 / F3 keys to highlight the
Set Integ.
Time Button, then press
↵
. The Integration Period dialog box shown in Figure 32 will then be
presented.
Figure 32: Integration Period Dialog Box