Abstract: In accordance with a method for calibrating structurally identical spectrometers for constituent analysis, a multiplicity of samples are provided and concentrations of one constituent in the individual samples are measured using a reference measuring method. Spectra of the individual samples are measured using one spectrometer selected from the structurally identical spectrometers to determine a preliminary regression model. At least one spectrum is selected from the measured spectra and/or a mean value spectrum formed from the measured spectra. A multiplicity of error spectra are generated using a mathematical model of the structurally identical spectrometers. The individual error spectra are added in each case to the individual selected spectra to obtain simulated spectra.