ABB LS4000 Operating Instructions Manual page 95

OI/LS4000/NH3/H2O-EN
Step Procedure
2 Click on "Toggle span mode".
The internal validation cell is swiveled into the beam path. This
process lasts a few seconds.
The measured value before the validation cell was swiveled in is
automatically subtracted (see step 1) from the now displayed
measured value for NH3 (40.28 ppm in the example).
If...
the measured value for NH3
does not differ by more than
± 10% from the set point,
the measured value for NH3
differs by more than ± 10% from
the set point,
The prerequisite for the correct display of measured value after
the validation cell is swiveled in is that the proportion of NH
process gas is as stable as possible.
The measured value for the transmission is lower with a validation
cell swiveled in than with a validation cell swiveled out (in the
example 70.39% compared to 81.41%).
Step Procedure
3 Click on "Toggle span mode".
The internal validation cell is swiveled out of the beam path. This
process lasts a few seconds.
4 Click on "Done" to exit the menu.
The analyzer returns back to normal measuring mode.
Operating instruction LS4000 for NH
then...
the analyzer is reacting correctly to the
sample component contained in the valida-
tion cell.
the analyzer must be inspected by an au-
thorized service technician.
and H O
3 2
in the
3
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