On-line high-accuracy particulate matter monitoring technology using multi-channel scattering signals

Particulate matter has adverse effects on the environment and human health, thus emission monitoring of particulate matter is essential for environment and human health protection. Optical methods are popular for on-line particulate matter emission monitoring due to their low cost, high sensitivity and easy maintainability. However, the measurement accuracy is susceptible to the particle size distribution of the particulate matter. To resolve this problem, a new optical method using multi-channel scattering signals and a proof-of-concept prototype sensor are proposed in this paper. According to multi-channel scattering signals, which reflect the change of particle size distribution, the prototype sensor adaptively sets the mass scattering coefficient to improve the mass concentration measurement accuracy. Compared with the state-of-the-art optical technologies, simulation results show that the relative standard deviation was reduced from 242% to 4% by our method. In the tests of our prototype sensor, the maximum relative measurement errors are 10% for di-ethylhexyl-sebacat (DEHS) monodisperse aerosols and 11% for coal smoke. Given that it is low cost, highly sensitive and easy to maintain, the new method has significant potential for precise measurement of particulate matter in mobile or stationary pollution monitoring applications. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement