Cubic-Ruiyi flue gas analyzers are based on Dual Beam NDIR/ Micro-flow NDIR/UV-DOAS/NDUV/TDLAS/ECD technologies for CO, CO2, CH4, SO2, NO, NO2, NH3, O2 measurement from PPM level to percentage, which are widely used in various applications, such as Boiler, furnace exhaust emission gas and combustion efficiency monitoring, cement production line process and security monitoring.