Metrohm 862 Compact Titrosampler - Manual (Page 106)

7.1 Dynamic equivalence point titrations (DET) ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
96 ￭￭￭￭￭￭￭￭ 862 Compact Titrosampler
V
E
pH
V/mL
Figure 30 Tubbs method for determining the equivalence point
The figure shows that the evaluation also requires measuring points from
the measuring point list after the equivalence point as well.
For the recognition of the EPs found the set EP criterion is compared with
the ERC (Equivalence point Recognition Criterion) found. The ERC is the
first derivative of the titration curve combined with a mathematical func-
tion which is more sensitive for flat jumps than for steeper ones. EPs
whose ERC is smaller than the defined EP criterion will not be recognized.
The ERC is displayed in the results dialog for each discovered and recog-
nized EP. If you adjust the EP criterion after the fact in order to recognize
more or fewer EPs, then you can initiate the reevaluation in the results dia-
log with the [Recalc] key.
7.1.5 Calculation
7.1.5.1 General
Menu ▶ Parameters ▶ Calculation
A maximum of five calculations can be defined in one method. A series of
variables (raw data from the determination, previously calculated results) is
available for the calculations. Definition can be made for each calculation
as to whether the result is to be saved as a titer or as a common variable.
The result name is specified in the list for each calculation.
Edit
Edit the data of the selected calculation, see following chapter.