Calibration method of ultra-low emission particulate concentration measurement by light scattering method

Abstract

Abstract To reduce the error caused by optical device pollution and background value drift in the measurement process of ultra-low emission particulate concentration by light scattering method, an on-line calibration method which can realize self-check and full-range calibration was put forward. The single light source spectral method was used to set up calibration light path, through a strong emphasis on technology achieving light signal extraction. The calibration effect was evaluated based on the dust tunnel system. The results show that the light intensity-modulated technique can significantly improve the measurement accuracy of low concentration particles compared with the constant light intensity technology. When the concentration of particles to be measured is higher than 500 μg/m³, the relative error between the measurement results of the experimental prototype and those of the filter membrane weighing method is less than 10 %. The optimal calibration period of the measuring instrument is 3 hours. When the variation deviation from the calibration light intensity of light intensity modulation is less than 2 %, the relative error between the particle concentration measurement result and the filter membrane weighing method is less than 10 %.