CO分子在4.6 μm 具有最强吸收峰, 以此作为气体吸收的中心波长, 结合光源EMS200光源的发光特性, 设计开放式的球面反射镜气室, 采用单探测器双通的结构, 研制了一种中红外差分式CO检测仪。利用模拟混合气站配备标准的CO气体浓度, 对该仪器的相关性能开展研究。研究表明: 仪器分辨率为20 ppm(1 ppm=10-6), 最低检测下限为18 ppm。CO浓度在30~1 500 ppm范围内, 其测量误差不超过8.5%。与激光光谱技术的CO检测仪相比, 该系统采用脉冲红外热光源, 其性价比高; 采用开放球面反射镜气室, 光路简单易于实现。所以该CO检测仪在煤矿开采、环境监测、石油化工等领域具有较高的实际应用价值。

CO molecules have the strongest absorption peak at 4.6 μm, which was selected as the central wavelength of the gas absorption. Combined with the luminescence characteristics of light source EMS200, spherical mirror chamber open was designed. A mid-infrared differential CO detection system was developed using the double pass structure of single detector. The performance of the instrument was studied by using the standard gas concentration of carbon monoxide in the mixed gas station. The research results reveal that, the resolution of the instrument is 20 ppm, and the limit of detection (LOD) is 18 ppm. The relative error was not more than 8.5% within the low concentration range of 30-1 500 ppm. Compared with the CO detection systems utilizing laser spectroscopy technology, pulsed infrared thermal source used in this system, its performance-cost ratio was high; with open spherical mirror chamber, the light path was simple and easy to implement. So the proposed detector shows potential applications in CO detection under the circumstances of coal-mine, environmental protection and petrochemical industry.