Algorithms

This is a simple method for correction of Mid IR spectra sampled using the ATR (Attenuated Total Reflectance) technique. It only corrects for the penetration depth dependence related to the frequency in the spectrum. It does not attempt to correct for the refractive index differences between the sample and the crystal that can lead to "derivative-like" spectra.

First a simple baseline correction is applied to remove offset by subtracting the minimum value in the spectrum from all data values:

Where:
Y is the trace values
i  is the point index

A good baseline is important for correct results. For best results it is recommended that a suitable Baseline Correction be applied to the data.

The penetration depth for each wavelength is then calculated from the following equation:

The array of values is than scaled as follows:

The spectrum is than corrected for penetration depth as follows:

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