title: Measuring trace impurities in air by infrared spectroscopy at 20 meters path and 10 atmospheres pressure.
mesh_terms: D000397:Air Pollution / Q000032:analysis*; D001274:Atmospheric Pressure; D006813:Humidity; D008697:Methane / Q000032:analysis; D008722:Methods; D009584:Nitrogen; D009787:Occupational Medicine / Q000295:instrumentation; D011108:Polymers; D011138:Polytetrafluoroethylene; D013055:Spectrophotometry, Infrared; D013458:Sulfur Dioxide / Q000032:analysis; D014131:Trace Elements / Q000032:analysis*; D014867:Water
chemical_list: D011108:Polymers; D014131:Trace Elements; D014867:Water; D013458:Sulfur Dioxide; D011138:Polytetrafluoroethylene; D009584:Nitrogen; D008697:Methane