Automatic calibration method

A method for automatically calibrating a spectrometer for evaluating spectra in the course of examination of solid, liquid or gaseous substances, said method comprising the steps of

• (a) acquiring a plurality of reference spectra of a plurality of samples,
• (b) storing said spectra in a spectral matrix,
• (c) treating said data and reducing the dimension of said matrix by at least one of
• (1) pretreating the data with a mathematical method,
• (2) selecting a specific wavelength, and
• (3) reducing the amount of data by application of a calibration method selected from the principal component analysis (PCA), PCR or PLS, thereby forming a first set of treated data and a first calibration model,
• (d) determining a first quality value of a calibration on the basis of said first set of treated data,
• (e) repeating the treating and determining steps for all possible permutations of pretreatment methods, wavelength ranges, and calibration methods, thereby forming repsective quality values,
• (f) selecting an appropriate calibration model on the basis of the best quality values.