超声脉冲测温技术初步研究

A preliminary study of pulse-echo ultrasonic thermometry

目前基于脉冲技术的超声测温研究主要侧重于超声换能器和系统硬件电路设计,而对高温敏感元件的研究较少。通过选取合适的敏感元件材料,以及对超声导波在杆中的频散特性和反射、透射分析,最终选用了一根长为1 m、直径1 mm左右的带反射凹槽的钍钨杆作为敏感元件,并在一个超声测温平台进行了初步的实验。实验结果表明,采用钍钨合金杆作为敏感元件,可有效测量12℃~1 600℃声速与温度的关系,所测得的高温下的声速与参考值相比误差不超过0.68%。

At present, the study of ultrasonic thermometry based on pulse-echo technology mainly focuses on the design of ultrasonic transducer and hardware circuit system, but the study of sensitive element at high temperature is less. In this paper, several appropriate sensor materials are evaluated, through the analysis of the dispersion characteristics and reflection of ultrasound in the rod. A 1 m long and 1 mm diameter of the thoriated tungsten rod with reflection groove is used as the sensor, and a preliminary experiment is carried out on an ultrasonic thermometry platform. The results show that the use of thoriated tungsten rod as the sensor, can effectively measure the relationship between velocity and temperature at 12 ℃ to 1 600 ℃, and the error of ultrasound measured at high temperature compared with the reference value is not more than 0.68%.