Hach-Lange TITRALAB 840_845 Reference Manual - Manual (Page 97)

Titra Lab ® TitraLab 840 and 845 Reference Manual
Page 97
Equivalent point
determination
(IP methods) Incremental addition of the titrant (Monotonic/Dynamic IP
methods):
• acquisition of the titration curve E (electrode) = f (volume of titrant
dispensed),
• determination of the first derivative curve using a smoothing proc-
ess (depending on the value set for IP filter),
• determination of the second derivative curve,
• determination of the maxima of the first derivative curve using the
IP filter parameter. These maxima correspond to the zeros of the
second derivative curve.
• determination of the equivalent point: for this point the maximum of
the first derivative curve must be equal to or greater than the preset
IP reject method parameter.
Figure 18: Determination of an equivalent point - Monotonic or Dynamic IP
method
An equivalent point is determined and plotted live on the titration
curve. The method is stopped after a given number of equivalent
points (1 to 4) has been detected.
E or pH