中文摘要：

进行了将超声波用于气体浓度测量的研究,依据超声波在不同浓度的气体中有不同声速的特性,提出了一种基于超声波的相位差测量气体浓度的方法.该方法采用检相式气体浓度测量原理,通过把超声波的速度变化转换成相位差变化,用测得的相位差变化来反映气体浓度的变化.完成了用超声波检测气体浓度的系统的设计,分析了影响超声波相位差法测量精度的主要因素——温度因素并提出了补偿方法.采用甲烷进行了浓度测量实验,实验结果表明该方法具有精度高、测量方便、成本低等许多常用检测方法不具备的优点,具有较好的应用前景.

英文摘要：

Ultrasonic was applied to the measurement of gas concentration, and a new gas concentration measurement method based on ultrasonic phase difference was proposed according to ultrasonic＇ s speed characteristic that the ul- trasonic speed changes with the gas concentration. The method adopts the phase detected principle for gas concen- tration, and transfers the ultrasonic speed changes into the changes of phase difference, using the obtained changes of phase difference to indicate the changes detecting system was also completed, and of gas concentration. The design of an ultrasonic based gas concentration the main factors affecting the gas concentration measurement accuracy, such as the temperature factor, were analyzed and the solutions were gaven. The results of the methane concentration experiment show that the detecting method has many advantages compared with other methods in common use, and it will have a brightly application prospect.