Hanna Instruments HI 901 - Manual (Page 57)

5-17
METHODS
2nd Derivative:
When second derivative is used to recognize the equivalence point, the zero crossing point of
the second derivative corresponds to the titration curve inflection point (EQP).
The detection algorithm searches for the point where the second derivative changes the sign.
Also, the first derivative, corresponding to the checked point must be greater than the
threshold value (see Recognition Options on page 5-17).
Recognition Options
The Recognition Options screen represents a set of parameters used to avoid false
detection of the equivalence point. This could appear mainly due to the chemical system
(involved titrant / sample chemical species and concentrations) and / or to the electrode
response.
The Recognition Options screen is available only when Equivalence End Point (pH or mV)
option is selected.