A device and process for measuring and analyzing spectral radiation within a desired wavelength range. A number of radiation sources are provided, in combination with a sensor for detecting radiation within the desired wavelength range. The radiation sources are selected to have spectral characteristics that are linearly independent from one another, but overlap so that, in combination, the radiation sources generate radiation over the entire desired wavelength range. Alternatively, a single radiation source generating radiation over the entire desired wavelength range is provided in combination with a plurality of sensors that have spectral sensing characteristics that are linearly independent from one another, but overlap so that, in combination, the sensors sense radiation over the entire desired wavelength range. Further provided is a control unit that stores a number of calibration functions with linearly independent spectral characteristics, the control unit further receiving output values from the sensors to determine the spectral characteristics of the object being measured.