Abstract: A method and apparatus for interpreting spectral data in an optical sensor for a variety of uses, such as the manufacture of paper. A probe is inserted into paper pulp during the manufacturing process. The probe emits light into the pulp which is then reflected back and received. This reflected light is segmented into N different wavelengths over the visible spectrum. An N signal array is created which is used in a mathematical model to accurately depict a brightness and consistency of the paper pulp.

Abstract: A method and apparatus for normalizing spectral data for an optical sensor. The sensor is comprised of a probe, a color sensor, a series of reflective targets, and a data processing means. Before the sensor is put into operation, a model is created, the use of which can normalize spectral data output by the color sensor for a variety of defined parameters. During operation of the sensor, the model maybe updated by rotating the targets individually in front of the probe. The targets have known reflectivities and the difference between the actual reflectivity and the spectral data is used to update the model.