Patent ID: 6202493
Filing Date: 2001-03-20
Classification: G01B,G01N

Abstract:
An apparatus for determining at least a first measurement parameter of an object, comprising:means for locating the object in a measurement interaction volume;at least one light source for passing a measurement light beam through the measurement interaction volume to interact with the object to produce measurement outgoing light, the measurement light beam comprising at least two spectrally different wavelengths of light;at least one detector to detect portions of the at least two measurement spectrally different outgoing light and to generate signals therefrom, whereby the signals are a function of the at least first measurement parameter, the detector being operatively associated with the light source;means for filtering the measurement outgoing light from the measurement interaction volume into at least two measurement spectrally different outgoing light portions, the means for filtering being operatively associated with at least one of the light source and the at least one detector; andmeans for determining the at least first measurement parameter from the signals, the means for determining being operatively associated with the detector, anda light absorbing background operatively associated with the measurement interaction volume and the at least one detector such that said at least one detector receives substantially only measurement outgoing light directly reflected from said object.