Metrohm tiamo 2.2 (ProcessLab) - Manual (Page 454)

5.6 Commands ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
438 ￭￭￭￭￭￭￭￭ tiamo 2.2 (ProcessLab)
5.6.3.2 DET
5.6.3.2.1 DET - Overview
Menu item: Method ▶ Paste ▶ 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 achieve constant measured value modifications
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 titra-
tion curve should not vary too much from an S-shaped curve.
Evaluation
Equivalence points EP are determined atuomatically 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 equivalence
point VE is shifted from the inflection point towards the smaller circle of
curvature for real asymmetric titration curves.