Ultrasonic Inspection System Using a Long Waveguide with an Acoustic Horn for High-Temperature Structure

• 作者: Kenshi Matsumoto Makiko Kobayashi Masayuki Kobayashi Riichi Murayama
• 来源期刊: 传感技术(英文)
• 学科: 医学
• 关键词: GUIDE WAVE WAVEGUIDE ACOUSTIC HORN NDI Thickness Measurement
• 年，卷（期）: 2014,（4）
• 页码范围: 177-185
• 页数: 9页
• 分类号: R73

摘要

The nondestructive inspection of a high temperature structure is required in order to guarantee its safety. However, there are no useful sensors for high temperature structures. Some of them cannot work at temperatures over 50°C. Another concern is that they are too expensive to use. A sensing system, which can transmit and receive an ultrasonic wave that travels a long distance using a long waveguide, has been studied. We confirmed that the optimal guided ultrasonic wave could travel more than 10 m using an electromagnetic transducer (EMAT) with a thin Ni-sheet surrounded on the surface of the bar and a 2-mm diameter bar as the waveguide. However, we had the difficult problem of receiving the reflected ultrasonic wave from the inside of a test specimen. We tried to improve the trial inspection system using an acoustic horn. An experiment in which the temperature of the test block was heated to about 500°C has now been completed. Finally, the condition of the bend in the waveguide to pass without reflection was confirmed.