1. A method of normalizing spectral data in an optical sensor comprising the steps of: providing a light illuminating and sensing means which outputs a signal proportional to the magnitude of the reflectivity of an object or substance which is being scanned by the optical sensor; providing at least one model manipulating means constructed with reference to testing of the light illuminating and sensing means for normalizing the output signal for a plurality of parameters which affect performance of the light illuminating and sensing means; illuminating the object or substance with light emitted from the light illuminating and sensing means; receiving light reflected off the object or substance and transmitting the reflected light to the light illuminating and sensing means; generating the proportional output signal; normalizing said proportional output signal through insertion of magnitude values of said signal into the normalization model manipulating means; periodically receiving reflected light of known and different reflectivities so that known magnitudes of said output signal are produced; and updating the normalization model manipulating means based on any change in magnitude of said output signal produced from said reflected light of known and different reflectivities.