Device and method for measuring extinction coefficient of black carbon aerosol

Abstract

The invention provides a device and method for measuring the extinction coefficient of black carbon aerosol. The device is a two-channel transmission-type atmospheric aerosol measuring device which has high long term reliability and can accurately measure the extinction coefficient of the atmospheric aerosol. The method is characterized by adopting the two-channel photoelectric detection technology and using the ratio of the transmissivity of the filtered gas to the transmissivity of the unfiltered aerosol gas to be detected to show the extinction coefficient of the aerosol and has the advantage of accurate measuring result. The method comprises the following steps: a laser diode (LD) is adopted to transmit a light pulse sequence, the light pulse sequence becomes parallel light after being collimated and is sent out and the light beam is split into two light beams with approximately equal strength with a beam splitter; after respectively passing through a measurement cell channel and a reference cell channel, the two light beams are respectively received by receiving units; the signal received by each channel is processed by a photoelectric signal processing unit and then is sent to a computer control unit by a data acquisition unit; and the computer control unit is used for computing the ratio of the light power detected by the two channels and carrying out logarithmic operation to obtain the extinction coefficient of the aerosol.

Description

technical field [0001] The invention designs a light radiation receiving and measuring device, in particular a transmission type atmospheric environment pollution measuring device, which belongs to the measuring device of extinction coefficient when light radiation energy propagates in the atmosphere. Background technique [0002] The pollution sources in the atmosphere are mainly aerosols and toxic gases. Black carbon aerosol is an important part of atmospheric aerosol, which is mainly produced by the incomplete combustion of carbon-rich substances, such as natural phenomena such as volcanic eruptions and forest fires, and the large-scale use of fossil fuels such as coal and oil by humans. Increase in black carbon aerosol emissions. Because black carbon aerosols have a strong absorption effect on solar radiation in the wavelength range from visible light to infrared, they have an important impact on regional and global climate. The 2000 IPCC (Intergovernmental Panel on Cl...

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Problems solved by technology

The 2000 IPCC (Intergovernmental Panel on Climate Change, United Nations Intergovernmental Panel on Climate Change) report pointed out that black carbon aerosols can lead to positive radiative forcing, thereby greatly weakening the cooling effect of aerosols on the earth

These methods and devices are basically single-channel, and the fluctuation of light source intensity and the change of detector performance will bring measurement uncertainty or error

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