Metrohm 757 VA Computrace - Manual (Page 125)

5.8 Data processing and evaluation
757 VA Computrace – Software
115
Peak recognition
With the derived curves a search is made for successive minima
and maxima. A maximum followed by a minimum indicates a
normal peak, a minimum followed by a maximum a reverse peak.
With the aid of these measured maxima and minima values, the
Peak voltage and Peak width values are determined for each peak.
After the peak detection a baseline is constructed. The Peak height
is determined from the value of the peak maximum minus the
value of the baseline at the position of the peak voltage.
Peak width
Minimum peak width
Peak position ± Tolerance
Peak voltage
Peak height
Umax Umin
Minimum peak height
i
di/dU
U
U
Derivative
Peak voltage = (Umax + Umin) / 2
Peak width =  Umin - Umax 
Peak height = Peak height at peak voltage
The peaks found are assigned to defined substances with the aid
of these approximate values and the recognition parameters
specified for the substances on the
Substances tab. The following
three recognition tests are performed:
Peak voltage test:
Peak voltage = Peak position ± Tolerance
Peak width test: Peak width > Minimum peak width
Peak height test: Peak height > Minimum peak height
If all three test conditions are met, this peak is assigned to the
corresponding substance and thus recognized as a substance
peak. In the curve display, this peak is marked with the substance
name "
Substance ".
If only the last two test conditions are met, this peak is recognized
as an unknown peak but not assigned to a substance. In the
curve display, this peak is marked with "
Unk ".