Metrohm tiamo 2.3 (process analysis) - Manual (Page 472)

5.6 Commands ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
456 ￭￭￭￭￭￭￭￭ tiamo 2.3 (for Process Analysis)
5.6.3.2 DET
5.6.3.2.1 DET - Overview
Menu item: Method ▶ Insert ▶ New command...
Command for Dynamic equivalence point titrations.
Principle
With this command titrations with dynamic incremental reagent addition
are carried out. The volume increments vary as a function of the slope of
the curve. An attempt is made to reach constant measured value modifi-
cations with each dosing. The optimal volume for dosing is determined
from the measured value modifications of the previous dosings. Measured
value acceptance is drift-controlled (equilibrium titration) or after a waiting
time.
Note
As the reagent addition in DET depends on the measuring data, the
titration curve should not vary too much from an S-shaped curve.
Evaluation
Equivalence points EP are determined automatically in a similar manner to
that described in the Tubbs method (C.F. Tubbs; Anal. Chem 26 (1954)
1670–1671, quoted in Ullman 5 (1980) 659). The volume of the equiva-
lence point VE is shifted from the inflection point towards the smaller cir-
cle of curvature for real asymmetric titration curves.