Her analysis gives an indication of the ratio of fuel-air mixture, and thus could help in setting up the carburetor. In the "primordial" gas analyzers used by the effect of changes in the electrical platinum coil in an environment of carbon monoxide. To the 70 th year, when the island was a question of control of emissions of vehicles, the level of technological development has allowed a more qualitative, two-component devices. They measured further concentration of another malware component – hc (unburned hydrocarbon particles that make up the fuel). By the way, the content of hydrocarbons (as well as oxides of nitrogen) is not determined as a percentage, as all other gaseous components, and ppm – the number of parts per million. In addition, we used a different, more accurate method of determining the concentration – spectrometry exhaust gases in the infrared range.
This same principle applies in modern analyzers. Further improvement of the gas analyzers was defined as ever stricter control of the toxicity and increasing demands to the device as a diagnostic tool. How else to explain the appearance of three-component gas analyzers, additionally allows to measure the concentration of carbon dioxide CO2, safe gas without color and odor, a natural product of combustion of hydrocarbons? Information about it does nothing, in terms of identifying hazards emissions. But is valuable for diagnosis, because it allows indirect information about the completeness of fuel combustion, even if the engine is equipped with catalytic converter exhaust. By the way, the equipment exhaust systems car catalytic converter has given considerable impetus to the development of devices gas analysis.