NETZSCH SEPARATION OF PEAKS is a program for evaluation of different types of data. With it, the experimental data are fitted as an additive superposition of peaks, where each single peak can be represented with the following types of profiles:

GAUSSIAN,

CAUCHY,

PSEUDO-VOIGT 
  (weighted mixture of Gaussian and Cauchy profile),

FRASER-SUZUKI (asymmetric Gaussian),

PEARSON -7 
  (monotonic transition from Gaussian to Cauchy profile).

Fraser-Suzuki profile with various values of asymmetry

Each single peak is characterized by three or four parameters:

- position,
- amplitude,
- half width,
- asymmetry (for Fraser-Suzuki profile only),
- slimness (for Pearson profile only).

For correction with a Baseline, the program offers TSCHEBYSCHEFF polynomials to a maximum of the 3rd degree.

The model is fit to the experimental data by means of a hybrid GAUSS-NEWTON procedure, where a Marquardt method is combined with a step length optimization. Two equally remarkable features of the algorithm are speed and stability.

The solution can be limited to a reasonable range through:

- free choice of lower and upper limits for each parameter and
- selection of Parameter Options constant, equal and designation.

ASCII Files serve as a general interface for the transfer of data.

Results of the evaluation are:

- the optimal parameters and their standard errors,
- statistical characteristic values such as the correlation coefficient 
  and the average fit error,
- graphic representation of the curve fit including the separated 
  single peaks,
- calculation of the areas of the single peaks and their percentage 
  of the total peak.
   

Program application areas are:

- thermal analysis (Differential Scanning Calorimetry and
  Thermogravimetric Analysis),
- UV/VIS spectroscopy,
- NIR and IR spectroscopy,
- NMR spectroscopy,
- X-ray small-angle scattering of polymers 
  (for profile analysis with a Pseudo-Voigt profile, the 
  Gauss component indicates the degree of crystallinity).