Patent ID: 7897923

Claim:
A method of non-destructively determining the physical property of a material surface comprising: irradiating a surface with infrared energy over a spectrum of wavelengths by a hand-held portable IR spectrometer; said hand-held portable IR spectrometer comprises an accessory calibration plate attachable over an IR signal collection port wherein said calibration plate comprises a reference sample comprising a condition approximating an actual sample wherein said physical property is present at a predetermined level; detecting said infrared energy reflected from said surface over said spectrum of wavelengths; performing multivariate analysis of said reflected infrared energy at a plurality of selected wavelengths comprising said spectrum of wavelengths; comparing results of said multivariate analysis with a predetermined correlation between model infrared energy spectra comprising said spectrum of wavelengths and a model material surface, said predetermined correlation with said model material surface comprising one or more physical properties of said model material; and, determining said one or more physical properties of said surface.