This is a term generally meaning the sum of nitric oxide and nitrogen dioxide. There are two widely used methods for measuring NO, infra-red and chemiluminescence, NO2 is then measured by first converting it to NO using a catalyst, to give a reading for the total NOx. NO and NO2 can also be measured at low levels in ambient air using electrochemical cell technology. This is a lower cost alternative but has limitations in terms of accuracy due to potential cross sensitivity and high temperature and humidity effects.
Non Dispersive Infrared (NDIR) Multi-gas analysers are available in 1, 2, 3, 4 or 5 gas channel configurations, offering high levels of performance and flexibility. Options include CO, CO2, CH4, NO, N2O, SO2, HCl and O2.
