On-line detecting method and apparatus for multi-component gas

Abstract

The invention provides a method for detecting on-line a multi-component gas and the testing arrangement for the method. The method comprises the following procedures: the current and temperature are tuned by a semi-conductor laser; after double modulation, the laser emitted from the semi-conductor laser passes an optic-fiber coupler, partial laser reaches to an open multi-optic-path pond, in which the emitted light that is absorbed by the gas to be measured is again transmitted through an optic fiber to a balance receiver; another partial laser from the optic-fiber coupler is also sent into the balance receiver; the signals picked up by the balance receiver is sent into a phaselocking amplifier after passing a pre amplifier, and then sent into a computer for processing after passing an A / D converter. The testing arrangement comprises a modulation signal generator, a laser driver, a laser spectrum light path, a signal conditioning circuit and a computer that are connected in sequence; the computer is additionally connected with the modulation signal generator, and connected with the laser spectrum optic path through a temperature detector / controller. The invention converts the precision controlling of temperature into the precision controlling of temperature, improves the sensitivity and opaqueness of the detection, so as to achieve the simultaneous testing of a plurality of components.

Description

technical field [0001] The invention relates to a gas detection device and method. In particular, it relates to a multi-component gas online detection method and device based on near-infrared tuned laser spectroscopy, which can be directly applied to real-time detection and analysis of on-line component analysis and concentration measurement of various gaseous components in the air without collecting gas samples. Background technique [0002] Air quality is related to ecological balance and human health and development. Various types of industrial and mining enterprises discharge a large amount of industrial waste gas, which poses a great threat to the ecological environment and human health and emits a large amount of waste gas mainly including: nitrogen oxides (NOx), sulfur dioxide (SO 2 ), phosphorus (P), carbon monoxide (CO), halogenated hydrocarbons, volatile organic compounds (VOCs) and other toxic gases. [0003] In my country's current ambient air quality monitorin...

AI Technical Summary

Problems solved by technology

Its disadvantages are: the on-site sampling is sent to the laboratory for analysis, which does not have the timeliness and mobility of the analysis, and the sampling and detection process is complicated; at the same time, the "point" sampling method can only give the instantaneous value of one point, and the data represents Poor sex

[0010] Since most of the VOCs in the environment are very low and belong to the micro and trace range, there is no mature VOCs continuous monitoring system product in the world, and there is no official official VOCs concentration limit.

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