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...

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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 valu

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