一种新的微量气体浓度检测方法

New Detection Method for Trace Gas Concentration

提出一种微量气体浓度检测的方法,利用单一气体中声速与温度关系,在测量温度时避免了直接测温所带来的测量误差。在测温电路中应用了全数字锁相环技术提高了超声波传播时间的测量精确度。以空气中SF6气体浓度为例在MATLAB环境里建立仿真模型,仿真结果表明:该测量方法的微量气体浓度检测精度达到10-6,相对误差不超过1%。

A new method for trace gas concentration detection was proposed,which having the relation between temperature and ultrasonic velocity in single gas based to avoid a direct measurement error; and the all-digital phase-locked loop technology applied in temperature measurement circuit can improve the accuracy of measur- ing ultrasonic propagation time. Taking SF6 gas concentration in air for example to detect the gas concentration and to establish the simulation model in MATLAB show that the precision of this method can achieve a 1 × 10^-6 level and the relative error is less than 1%.