Dry-coupled ultrasonic waveguide transducers enable the long-term monitoring of the critical mechanical components working in high temperature environment. In these systems, waveguide units are applied to isolate the vulnerable piezoelectric elements from the harsh measurement zones. However, the disturbance cannot be overcome, which may arise from inevitably temperature fluctuation and the indirect measurement in long term monitoring. In the present research, a high temperature experimental system using dry-coupled ultrasonic waveguide transducers is investigated. The disturbances caused by this measurement system are studied in the heating period, holding period and cooling period, respectively. Moreover, the correlations between the group velocities, dispersion curves, signal amplitudes, waveforms under temperature variations are investigated. At last, the dispersion characteristics of the shear horizontal wave in high temperature stainless steel plate are analyzed. This work strives to pave a solid foundation for the application of SH waves to online monitoring of high-temperature equipment using dry-coupled ultrasonic waveguide transducers.

中文翻译：

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使用干耦合超声波波导换能器监测高温设备的特性

干耦合超声波换能器能够对在高温环境下工作的关键机械部件进行长期监测。在这些系统中，波导单元用于将脆弱的压电元件与恶劣的测量区域隔离。然而，这种干扰是无法克服的，这可能是由不可避免的温度波动和长期监测中的间接测量引起的。在目前的研究中，研究了使用干耦合超声波波导换能器的高温实验系统。分别在加热期、保温期和冷却期研究了由该测量系统引起的扰动。此外，研究了群速度、色散曲线、信号幅度、温度变化下的波形之间的相关性。最后，分析了高温不锈钢板横向横波的频散特性。这项工作力求为SH波在干耦合超声波波导换能器高温设备在线监测中的应用奠定坚实的基础。