论文部分内容阅读
利用上位机及Labview工作平台数据处理能力强的优势,实现了一种针对甲烷(CH_4)气体的双通道差分式中红外检测系统。采用IRGJ型双通道传感器(英国E2V公司,3.31μm和3.90μm)检测气体浓度变化,利用Labview和数据采集(DAQ)卡(PCI6 221)实现对探测器输出信号的采集和处理,采用二阶巴特沃斯数字滤波器滤除噪声以提高信噪比(SNR),对系统硬件和软件进行了集成。系统具有信号采集、滤波、幅值提取、浓度计算、存储及网络发布等功能。配备了不同浓度的CH_4气体样品,开展了标定实验,并测量了系统的精度、稳定性和检测下限等指标。实验结果显示,系统对CH_4气体的测量范围为0～5%,对9种气体样品的检测误差均小于6%。受传感器自身光程的限制,系统的检测下限约为60×10~(-6)。对浓度为2 000×10~(-6)(0.2%)的气体进行了长达4 h的浓度检测,除个别突变点外,检测的最大误差小于10%。由于数据处理能力强,系统功能不受资源限制并可任意扩展。
Based on the advantage of strong data processing ability of PC and Labview platform, a dual channel differential mid-infrared detection system for methane (CH4) gas was realized. The change of gas concentration was detected by IRGJ dual-channel sensor (E2V, 3.31μm and 3.90μm, UK). The detector output signal was collected and processed by Labview and DAQ card (PCI6221) Voss digital filters filter noise to improve signal-to-noise ratio (SNR) and integrate system hardware and software. System with signal acquisition, filtering, amplitude extraction, concentration calculation, storage and network publishing and other functions. Equipped with different concentrations of CH_4 gas samples, carried out calibration experiments, and measured the system accuracy, stability and detection limit and other indicators. The experimental results show that the measurement range of CH_4 gas is 0 ~ 5% and the detection error of 9 gas samples is less than 6%. By the optical path of the sensor itself, the detection limit of the system is about 60 × 10 -6. The gas concentration of 2 000 × 10 -6 (0.2%) was tested for 4 h. The maximum error of detection was less than 10% except for the point of mutation. Due to the strong data processing capability, the system functions are not limited by resources and can be expanded arbitrarily.