Metrohm 875 KF Gas Analyzer - Manual (Page 26)

4.2 Methods
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￭ Gas calibration_gas
￭ Shut down system
￭ Drift diagnosis
￭ System preparation
The following methods form part of the optional scope of delivery:
￭ Rinsing with solvent
￭ Reagent replacement
￭ Addition of methanol
NOTE
Please note:
The tiamo™ method can only be run if the Flow program has been
started.
4.2.1 Sequence of the "Sample measurement" method
The water content determination of the samples is controlled by the Sam-
ple measurement method, which basically consists of three steps:
￭ Prerinsing the line route with nitrogen
￭ Feeding in the sample
￭ Postrinsing with nitrogen
The method is designed in such a way that the pressure prevailing in the
area before the regulator (line volume between precision control, nitrogen
and sample valve) is released during the change from prerinsing to sample
introduction and from sample introduction to postrinsing. In this way, a
mixing of nitrogen and sample that could result in faulty measurements is
prevented. The entire sequence is shown in (see Table 4, page 18).
The flow diagrams of the analysis are visualized in figure 6. Some partial
steps are only run through if the corresponding scans are set to "yes" in
the sample table. The dosing device for methanol addition and reagent
replacement as well as for the automated rinsing with solvent is an
optional equipment of the 875 KF Gas Analyzer.
Table 4 Gas conveyance and valve control during the analysis
Partial step Condition Opened valves Stop condition
Prerinsing with sam-
ple Method variable "first
sample measure-
ment?" is set to "yes" Sample valve
Waste gas valve
90 seconds expired