Calibration material and method for calibrating spectral responsivity of raman spectrometers

A method of calibrating at least one Raman spectrometer, which at least one Raman spectrometer includes a monochromatic light source configured to transmit excitation light having a desired excitation wavelength to a measurement region, which is configured to accommodate a sample of a medium, and to illuminate the sample with the excitation light, and a spectrometric unit configured to receive measurement light emanating from the illuminated sample and configured to determine and to provide intensity spectra of the received measurement light in a spectral measurement range, the method comprising:

• providing a calibration material comprising:
• a reference material configured to emit a broadband spectrum of luminescence light in response to the excitation light;
• and
• an additional material, which exhibits a distinct Raman band within the spectral measurement range of the at least one Raman spectrometer to be calibrated;
• for at least two different temperatures, determining an emission spectrum of light emitted by the calibration material at each respective temperature in response to the calibration material receiving excitation light having the excitation wavelength;
• and
• calibrating each of the at least one Raman spectrometers by:
• with the respective Raman spectrometer, determining a calibration spectrum of the calibration material;
• based on the Raman band, which is included in the calibration spectrum, determining a temperature of the calibration material by performing a Raman thermometry method;
• and
• adjusting a determination of spectral intensity values of intensity spectra performed by the respective Raman spectrometer, wherein the adjusting is based on the calibration spectrum, the temperature of the calibration material during the determination of the calibration spectrum, and the previously determined emission spectra of the calibration material.