Study on Concentration Measurement of NO and NO2 Gases Using Quantum Cascade Laser Absorption Spectroscopy

Recently, the increasing interest in ultrafine particles has prompted studies of the mechanisms of the generation of ultrafine particles. The mechanism starting from nitrogen oxides (NOx) is one of the major mechanisms of ultrafine particle production. Ultrafine particles can form easily from NOx, which is generated by energy and power systems in the surroundings, such as vehicle exhaust, power plants, and incineration plants. On the other hand, it is difficult to measure NO and NO2 gases in real time, as well as analyze how many ultrafine particles are formed by its precursor. This paper reports the application of absorption spectroscopy to measure the concentrations of NO and NO2 gases using a quantum cascade laser. The experiments were performed on a white type multipass cell and the wavenumbers of the quantum cascade laser were 1851 cm(-1) and 1612 cm(-1).