Remote spectrophotometer

A spectrophotometer for measuring a distant sample comprising

• a high intensity pulsed Xenon illumination source;
• condenser lens means for receiving illumination from said illumination source and transmitting said illumination;
• aperture defining means in the optical path of said illumination transmitted by said condenser lens means;
• illumination lens means for uniformly illuminating an area of a distant sample to be measured by projecting an image of said illumination from said aperture defining means onto said sample area;
• reference beam means disposed in the optical path of said illumination between said aperture defining means and said illumination lens means for obtaining an illumination reference beam;
• polychromator means;
• image directing optical means for sequentially directing said reference beam and a reflected image of a substantial portion of said illuminated sample area towards said polychromator, the reflection angle between said illumination directed toward said sample and said reflected sample image being relatively small, said relatively large illuminated sample and reflected image areas and said small reflection angle providing a large depth of field;
• image focusing optical means disposed in the optical path between said image directing optical means and said polychromator means for focusing light directed from said image directing optical means onto said polychromator means, said image focusing optical means effectively averaging said reflected image of said uniformly illuminated sample area;
• analyzing means connected to said polychromator means for analyzing said reference beam and said reflected sample image over a range of wavelengths to determine the spectral characteristics of the sample.