分段幂函数模型在气敏检测器定量算法中的应用

Application of piecewise power function model in quantitative algorithm of gas sensitive detector

针对传统半导体气敏检测器电阻直接定量算法误差大、适应性差的问题,利用半导体传感器电导率随气体体积分数变化而变化的特点,提出了新的电路模型。通过对其特性曲线进行深入分析,构建了检测电路输出信号与气体体积分数之间的分段幂函数模型。先通过对不同体积分数气体进行采样,将采样气体体积分数和电路输出信号进行分段幂函数模型拟合,然后用拟合参数去计算未知检测气体的体积分数。实验结果表明:提出的定量模型大大提高了定量分析的准确性,且定量误差不受传感器漂移的影响,具有很强的环境适用性,提高了微量可燃气检测的可靠性和精度。

Aiming at problem of directly quantitative algorithm of semiconductor gas sensitive detector resistance owns the disadvantages of great error and poor adaptability,and using the characteristics that the conductivity of semiconductor varies with gas volume fraction,a new circuit model is proposed. A piecewise power function model between output signal of detection circuit and the gas volume fraction is constructed based on the deep analysis of the characteristic curve. To start with,sample the different volume fraction of gas and piecewise power function model fit the sampling gas volume fraction and output signal of the circuit. Then,use the fitting parameters to calculate the volume fraction of unknown detected gas. Experimental results show that veracity of quantitative analysis is greatly enhanced by using the proposed quantitative model. Moreover,quantitative error is unaffected by the drift of sensor. The proposed model owns a strong environmental suitability and the reliability and precision of the detection of trace gas are enhanced.