Particulate matter concentration measuring system in low-concentration particulate matter on-line tester

Abstract

The invention provides a particulate matter concentration measuring system in a low-concentration particulate matter on-line tester, belongs to the technical field of particulate matter detection, and solves the technical problems to provide a particulate matter concentration measuring system with high measuring accuracy and small measuring error in the low-concentration particulate matter on-line tester. The adopted technical scheme is as follows: the particulate matter concentration measuring system in the low-concentration particulate matter on-line tester comprises a power circuit board, an analog circuit board and a digital circuit board, wherein the power circuit board is used for supplying power to the analog circuit board and the digital circuit board; the analog circuit board comprises a laser, a laser light-emitting circuit and a signal conditioning circuit, the digital circuit board comprises a master control circuit, a voltage-current conversion circuit and a communication circuit, and the laser light-emitting circuit, the signal conditioning circuit, the voltage-current conversion circuit and the communication circuit are respectively connected with the master control circuit; the particulate matter concentration measuring system in the low-concentration particulate matter on-line tester is suitable for the field of environmental monitoring.

Description

technical field [0001] The particle concentration measurement system in the low-concentration particle online tester of the invention belongs to the technical field of particle detection. Background technique [0002] In the field of environmental protection, the data accuracy of online particle monitoring instruments is very important, and it is the only indicator to evaluate the treatment effect of pollution source control facilities; at present, the mainstream product in China is the in-line backscattering laser particle tester. However, the data accuracy of the measuring instrument is affected by various factors such as: dust humidity, particle size and other factors, resulting in low measurement accuracy and large measurement errors. [0003] Specifically reflected in the original particle tester test circuit: [0004] The power supply noise of the power supply part is large, generally 10mV, and can only be powered by 24V. If the power supply is too long, it will easil...

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Problems solved by technology

[0004] The power supply noise of the power supply part is large, generally 10mV, and can only be powered by 24V. If the power supply is too long, it will easily cause the power supply to become hot; for the analog circuit part, ordinary amplifiers are generally used for amplification and filtering. The multiple requirements are very large, resulting in large temperature drift and time drift; the current output circuit part generally uses ordinary "amplifier + triode" for current output, and the output current linearity is poor

[0005] In summary, the original on-line particulate matter tester is only suitable for testing high-concentration particulate matter, not suitable for testing low-concentration particulate matter. Therefore, a tester that can perform online testing for low-concentration particulate matter is particularly important

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