A method of evaluating the surface of a material that has a
distinguishable infrared spectrum comprising (a) positioning an infrared
fiber optic probe to be in contact with a surface of the sample or
material at a region of interest for detecting attenuated total
reflectance or within a sufficient distance from the surface of the
region for detecting reflection, (b) detecting mid- or near-infrared
radiation attenuated total reflectance or reflection off of the surface
of the sample or the material, (c) analyzing the infrared radiation from
step (b) for at least one of peak height, peak area, frequency and
chemometric parameters, and (d) actuating the removal device when a
signal from the infrared fiber optic probe is between pre-selected values
for at least one of peak height, peak area, frequency and chemometric
parameters for the sample of the material.