Exhaust gas analyzer Exhaust gas analyzer An exhaust gas analyser or exhaust CO analyser is an instrument for the measurement of carbon monoxide among other gases in the exhaust, caused by an incorrect combustion, the Lambda coefficient measurement is the most common. The principles used for CO sensors (and other types of gas) are infrared gas sensors (NDIR) and chemical gas sensors. "Carbon monoxide sensors are" used to assess the CO amount during an MOT test. In order to be used for such test it must be approved as suitable for use in the scheme. In UK a list of acceptable exhaust gas
Diesel exhaust U.S. 2010 emissions criteria, selective non-catalytic reduction (SNCR), and exhaust gas recirculation (EGR). Both are in the exhaust system of diesel engines, and are further designed to promote efficiency. Selective catalytic reduction (SCR) injects a reductant such as ammonia or urea — the latter aqueous, where it is known as diesel exhaust fluid, DEF) — into the exhaust of a diesel engine to convert nitrogen oxides (NO) into gaseous nitrogen and water. SNCR systems have been prototyped that reduce 90% of the NO in the exhaust system, with commercialized systems being somewhat lower. SCR systems do not necessarily need particulate