Multiple Pass Gas Absorption Cell

Technology Description

The NASA Ames Research Center has developed a gas absorption cell technology for compact multiple pass, open path gas absorption measurements in a compact space using an extended light source, such as thermal, hot filament or gas discharge.

Optical sampling cells are commonly utilized in IR spectrophotometers to measure low concentration of gases having very faint absorption bands, using the Beer-Lambert relation. Currently employed technologies, such as single and multiple pass sampling cells, have a number of limitations which diminish their effectiveness as analytical tools. The subject invention has a number of advantages over previous technologies. For example, the multiple pass gas absorption sampling cells provide a long optical path length in a relatively small volume. The sampling cell requires fewer passes thereby allowing the introduction of substantial quantities of light passing through the sampling cell which facilitates higher precision measurements. It also greatly reduces the possibility of light passing through unintended paths thus allowing accurate measurement of the path length, which in turn allows for a more precise measurement of gas.

The multiple pass gas absorption cell provides a convenient, portable, scalable and more reliable alternative to existing technologies for efficient gas measurement. In addition, this technology can be easily implemented since it allows for various methods of assembly, including selection of light source. This invention can find several applications dealing with accurate measurements of gas in the atmosphere, outer space, or even in a condensed fluid. Potential industries include Scientific Instruments and Environmental Analysis Equipment manufacturers.

Additional Resources

• Patent Document
• NASA Tech Briefs Article,  October 1997 vol 21 no10, pg. 52.

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