Laser backscattering dust meter with background light compensation function and using method thereof

Abstract

The invention provides a laser backscattering dust meter with a background light compensation function, which comprises a beam splitter prism, a photoelectric detector and a shielding mechanism, wherein the beam splitter prism is arranged on a light path of a laser beam emitted by a laser source and used for splitting the laser beam into two beams, one beam is calibration light, and the other beam is measurement light; the calibration light is emitted into the chimney and generates light spots on the inner wall of the chimney, and the measurement light is emitted into the chimney and acts with the particulate matter to form back scattering light; the photoelectric detector is used for receiving light signals of the light spots or the back scattering light; and at the same time, only one light beam can enter the chimney through the shielding mechanism. The invention also provides a using method of the laser backscattering dust meter with the background light compensation function. The laser backscattering dust meter has the beneficial effects that the beam splitter prism and the shielding mechanism are additionally arranged on the basis of an existing laser backscattering dust meter, and the background light correction coefficient which is automatically updated in real time can be obtained on line in cooperation with the using method of the laser backscattering dust meter, so that an accurate measurement result is ensured to be obtained.

Description

technical field [0001] The invention relates to the technical field of laser dust measurement, in particular to a laser backscattering dust meter with a background light compensation function and a use method thereof. Background technique [0002] In the application of particle detection of fixed pollution sources, if the temperature of the chimney is particularly high (over 200°C), it will be very advantageous to use a laser backscatter dust meter with easy installation and strong adaptability for dust concentration detection. Existing laser backscatter dust detectors such as figure 1 As shown, the laser beam 6 emitted by the laser source 3 is injected into the chimney 1, and the laser beam 6 interacts with the particulate matter 2 in the chimney 1 to produce scattering. When the concentration of the particulate matter 2 increases, the total scattering cross-sectional area of ​​the particulate matter 2 increases. The scattered light 7 is enhanced, that is, the dust concent...

AI Technical Summary

Problems solved by technology

However, the background light brought by the inner wall of the chimney 1 will change with the change of working years, climate and even working conditions, resulting in serious zero point drift of the photodetector 4

[0003] In order to obtain an accurate background light correction coefficient, the existing solutions are: 1) Set a zero-point drift compensation device, usually a potentiometer or a digital register, to manually compensate the drift. The problem is that there is a risk of environmental fraud; 2) Using dual detectors to compensate zero drift through real-time differential method, the problem is that the optical path is complex, the optical path adjustment and dual detector balance calibration are very difficult, and the shock resistance is poor

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