微弱气体浓度检测的弛豫平滑处理算法

研究了气体分子碰撞能量转移模型和弛豫声衰减理论。分析了混合气体中某些成分的浓度低于0.01%时，分子复合弛豫声衰减系数与气体浓度的模型变为崎岖不平的原因。利用信号处理中的滤波方法，使用平滑窗处理弛豫声衰减结果，改善了弛豫声衰减理论。得到了检测三元混合气体中微弱气体浓度的算法，检测浓度达到0.001%。设计了3种不同权重的平滑窗，均可降低由微弱浓度引起的检测误差扩大，其仿真结果一致证明弛豫平滑处理算法的合理性。

Relaxational Smooth Processing for Detection of Weak Concentration Gas

By analyzing the energy transfer models in molecular collision processes and the acoustic relaxation attenuation in gas, we find the reason of ruggedness in the dependence of molecular multi-relaxation attenuation coefficient on the mixture concentrations when the gas constituents have concentrations less than 0.01%. We use a typical smooth window to process acoustic relaxation attenuation data, and develop an algorithm to detect weak gas concentration of three-component gas mixtures. The measuring accuracy of this method achieves 0.001%. Three designed matrices with different weighted averages can all reduce errors resulting from weak gas concentration. The simulation results of consistent error-reduction using all the matrices show that the relaxation smooth processing algorithm is reasonable.