baseline drift
Baseline Drift
The baseline drift of a spectrometer is the overall deviation from the mean baseline regression due to temperature changes. As the temperature increases, the effect of dark noise will increase. However, depending on the (different) Detector, the electronic compensation may either increase or decrease with temperature. The Sony ILX511B Detector is a typical example of baseline degradation with increasing temperature, as the effect of negative electron compensation masks a small baseline increase due to dark noise. In theory, a change in temperature could have an equal and opposite effect on the Detector, so there would be no baseline drift.
baseline noise
Baseline Noise
Baseline noise is the sum of readout noise, dark noise, and electrical noise. The specification of the baseline noise is (obtained by the following steps), first set the integration time of the spectrometer to the minimum (to reduce dark noise as much as possible) for measurement, then isolate all light entering the spectrometer, and record 100 spectral values. The mean of the standard deviation of each single pixel output provides the minimum baseline noise of the device. Baseline noise is not a figure of merit, but it can be used to calculate dynamic range.
Baseline regression (baseline compensation)
Baseline Offset
Baseline regression refers to the value displayed by the instrument when there is no light incident. These values are slightly different for each pixel of the Detector. The final shape of the regression difference from cell to cell forms the fixed image noise. Baseline regression has three basic contributing factors: electronic compensation, dark current, and readout noise. A single average for the instrument can be calculated by averaging all the baseline regressions across the Detectors.
