一种基于涡流法超声换能器振幅测量仪的设计

Design of an instrument for measuring the amplitude of ultrasonic transducer based on eddy current method

对基于涡流法超声换能器振幅测量仪进行设计。该仪器由测量支架和测量仪本体构成,其中测量支架用于固定被测超声换能器,并将涡流传感器准确地设置于正对超声换能器输出端面的某一距离上。在高频振荡器作用下,换能器端面输出的超声频振动被涡流传感器转化为调幅信号,其所含调制信号的幅度即近似正比于被测换能器的振幅。该调幅信号经过高频放大、幅度检波、有效值变换、模数转换后成为数字量,再经单片机线性化处理后用液晶显示器给出测量结果。本研究结果在交通数据的采集中具有重要意义。

In this paper,the design of ultrasonic transducer amplitude measurement instrument based on eddy current method is studied.The measuring instrument consists of a measuring bracket and a measuring instrument body,of which measuring bracket is used to fix the ultrasonic transducer under test,and the eddy current sensor is accurately located at a certain distance from the output surface of the forward ultrasonic transducer.Under the action of high frequency oscillator in the measuring instrument body,ultrasound frequency vibration output from transducer end surface is converted into amplitude modulation signal by eddy current sensor.The amplitude of the modulation signal is approximately proportional to the amplitude of the transducer under test.After high frequency amplification,amplitude detection,RMS conversion and analog-to-digital conversion,the AM signal becomes a digital quantity.The result of measurement is given by LCD after linearization of MCU.