US 12,228,451 B2
Spectrometer with self-referenced calibration
Scott Sanders, Madison, WI (US)
Assigned to Wisconsin Alumni Research Foundation, Madison, WI (US)
Filed by Wisconsin Alumni Research Foundation, Madison, WI (US)
Filed on Aug. 10, 2022, as Appl. No. 17/885,042.
Prior Publication US 2024/0053198 A1, Feb. 15, 2024
Int. Cl. G01J 3/02 (2006.01); G01J 3/10 (2006.01); G01J 3/42 (2006.01); G01N 21/35 (2014.01)
CPC G01J 3/0297 (2013.01) [G01J 3/0208 (2013.01); G01J 3/0224 (2013.01); G01J 3/108 (2013.01); G01J 3/42 (2013.01); G01N 21/35 (2013.01); G01N 2021/3595 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An absorption spectrometer comprising:
a light detector and a light source providing a beam directed along a path;
a sample holder providing a chamber adapted to hold a sample in the path through which the beam may pass, the sample holder movable to change the length of the path through the sample between a first and second length;
an electronic processor communicating with the light detector to make measurements of light intensity of light along the path at the first and second length to provide an output indicating absorption of light by the sample isolated from variations in light from influences outside of the sample; and
wherein the chamber provides an entrance window accepting the beam from the light source into the sample and an exit window discharging the beam from the sample to the light detector, wherein the sample holder moves the entrance window with respect to the exit window to change a distance therebetween.