Rueter Dirk
Institute of Measuring and Sensor Technology, University of Applied Sciences Ruhr-West, 45479 Muelheim, Germany.
Sensors (Basel). 2017 Apr 22;17(4):926. doi: 10.3390/s17040926.
This experimental study demonstrates for the first time a solid-state circuitry and design for a simple compact copper coil (without an additional bulky permanent magnet or bulky electromagnet) as a contactless electromagnetic acoustic transducer (EMAT) for pulse echo operation at MHz frequencies. A pulsed ultrasound emission into a metallic test object is electromagnetically excited by an intense MHz burst at up to 500 A through the 0.15 mm filaments of the transducer. Immediately thereafter, a smoother and quasi "DC-like" current of 100 A is applied for about 1 ms and allows an echo detection. The ultrasonic pulse echo operation for a simple, compact, non-contacting copper coil is new. Application scenarios for compact transducer techniques include very narrow and hostile environments, in which, e.g., quickly moving metal parts must be tested with only one, non-contacting ultrasound shot. The small transducer coil can be operated remotely with a cable connection, separate from the much bulkier supply circuitry. Several options for more technical and fundamental progress are discussed.
本实验研究首次展示了一种固态电路及设计，该设计用于一个简单紧凑的铜线圈（无需额外庞大的永久磁铁或电磁铁），作为一种非接触式电磁超声换能器（EMAT），用于兆赫兹频率下的脉冲回波操作。通过换能器0.15毫米的细丝，高达500安培的强烈兆赫兹脉冲将脉冲超声发射到金属测试对象中。紧接着，施加100安培更平滑且类似“直流”的电流约1毫秒，以便进行回波检测。简单紧凑的非接触式铜线圈的超声脉冲回波操作是全新的。紧凑换能器技术的应用场景包括非常狭窄和恶劣的环境，例如，在这种环境中，快速移动的金属部件必须仅通过一次非接触式超声检测来进行测试。小型换能器线圈可以通过电缆连接进行远程操作，与体积大得多的供电电路分开。文中还讨论了实现更多技术和基础进展的几种选择。
