Patent ID: 7671985

Claim:
A device for small spot analysis by diffuse reflection spectroscopy using fiber optic interfaced spectrometers comprising: a) an internal radiation source, said radiation diverging from said source into substantially all directions, b) an axially symmetric ellipsoid chamber mirror having two segments near the poles cut away perpendicular to the axis of said chamber mirror so that one focal point of said chamber mirror is near the upper cutout but still inside the space enclosed by the surface of said chamber mirror while the other focal point is near the lower cutout and protruding slightly outside said chamber mirror and said chamber mirror having a small hole drilled near the equator of said chamber mirror perpendicular to said axis, the first focal point containing said source so that by the property of ellipsoid mirrors most of said radiation emitted by said source is refocused into the second focal point within a spot less than 1 mm in diameter, said second focal point being the sampling spot wherein a sample is introduced for analysis, c) an ellipsoid collecting mirror shaped as a segment of a 90° off-axis ellipsoid positioned inside said chamber mirror above said sampling spot so that one focal point of said collecting mirror coincides with said sampling spot and the other focal point coincides with said hole in said chamber mirror so that radiation diffusely reflected from said sample in the first focal point of said collecting mirror is, by the property of ellipsoid mirrors, refocused into the second focal point of said collecting mirror and can escape outside said chamber mirror through said hole, d) a fiber optics interfaced spectrometer placed outside said chamber mirror having an entrance slit positioned near said hole and in position to receive said diffusely reflected radiation from said collecting mirror either directly or relayed through an optical fiber from the second focal point of said collecting mirror to said entrance slit of said spectrometer to spectrally analyze said diffusely reflected radiation.