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TDLAS(Tunable Diode Laser Absorption Spectrometry)——可调谐半导体二极管激光吸收光谱技术是国际上逐渐兴起的一项新型气体检测技术。该技术使用激光束穿过气体后的衰减进行检测,但激光束只被“特定频率”的气体所大幅吸收,因此具有更高的检测灵敏度和更优的单一气体选择性,而且反应速度快、抗干扰能力强、工作稳定性高。本文主要设计了一种用于CO_2气体检测的激光器驱动模块电路。采用ARM7系列的LPC2148作为主控芯片,驱动DAC7513E来产生锯齿扫描信号,同时驱动AD9851产生调制所需的特定频率的正弦波,通过OP27进行两者信号叠加,用以驱动激光器,之后将各节点信号通过AD7928进行采样回传监控。该模块电路可以使用RS485通讯来控制相关参数及数据回传,不仅可以用于CO_2气体检测,还可以推广应用到其他气体检测。
Tunable Diode Laser Absorption Spectrometry (TDLAS) - Tunable Diode Laser Absorption Spectrometry (TDLAS) is a new type of gas detection technology that is gradually emerging in the world. The technique uses the attenuation of the laser beam as it passes through the gas, but the laser beam is only greatly absorbed by the “specific frequency” gas and thus has higher detection sensitivity and better single gas selectivity, and the reaction speed Fast, anti-interference ability, high work stability. This paper mainly designs a kind of laser drive module circuit for CO2 gas detection. Adopt ARM7 series LPC2148 as the master chip to drive the DAC7513E to generate the sawtooth scan signal, and drive the AD9851 to generate the sine wave of the specific frequency required for modulation. The two signals are superimposed by the OP27 to drive the laser, and then the signal of each node Through the AD7928 sampling return monitoring. The module circuit can use RS485 communication to control the relevant parameters and data return, not only for CO_2 gas detection, but also can be extended to other gas detection.