But is this internal calibration really essential? I think one calibration at the starting of the process is enough. What do you think about?
Calibrations are reasonably important with spectrometers, particularly in regard to emissive measurements, due to the temperature sensitivity of the sensor (dark noise). If (for instance) a display is warmer than the environment, it can be an advantage to "acclimatize" the instrument on the display for some time before making measurements. Graeme Gill.