Experience HORIBA, the Global Single Source Solutions Provider with over 50 years of technological advancements and unparalleled reliability, dependability and operability. The GI-700 stack gas analyser is designed to continuously measure the concentrations of nitrogen oxides (NOx), sulphur dioxide (SO2), carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), and ammonia (NH3) in stack flue gas streams.