Metrohm tiamo 2.4 (process analysis) - Manual (Page 876)

5.6 Commands
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tiamo 2.4 (for Process Analysis)
5.6.3.8 STAT
5.6.3.8.1 STAT - Overview
Menu item: Method ▶ Insert ▶ New command...
Command for STAT titrations.
Principle
In STAT titrations, reagent is added until a preset measured value (control
point) has been reached, which is then maintained at a constant level.
Because the substance that is released as a result of the reaction is imme-
diately titrated off with the titrant, the STAT controller has to be able to
maintain a preset control point at a constant level until the preset stop
condition has been reached, i.e. without oscillating around the control
point.
STAT titrations are used, for example, in enzyme analysis, where the
enzyme activity can be determined from the resulting dosing rate (in
mL/min).
Reagent dosing takes place in two phases during the titration:
￭ Dosing outside the control range
The dosing rate increases continuously during this phase. It starts with
the Min. rate and increases to the Max. rate. The dosing continues
to be carried out at the Max. rate until the control range (see Chapter
5.6.3.8.2, page 862) is reached. In this range, the controlling of the
STAT is the same as that of the SET.
￭ Dosing inside the control range
The STAT controller compensates minimal measured value deviations
from the control point quickly by dosing in the control range faster
than for the SET controller.