Transmissometers; opacity monitors; scattered-light meters; spectrometers; photometers; flame ionization detectors; gas analyzers for laboratory and industrial purposes; analyzers for analyzing hydrocarbons; oxygen sensors for laboratory and industrial purposes; gas analyzing systems comprised of a combination of transmissometers, opacity monitors, scattered-light meters, spectrometers, photometers, flame ionization detectors, gas analyzers for laboratory and industrial purposes, analyzers fo...