针对金属腐蚀声发射信号检测要求,设计并实现了一种低噪声的声发射信号调理系统。该系统由电荷放大电路、电压放大电路和滤波电路组成。详细论述了各部分电路的原理,并分析了电路噪声水平。分析试验表明,电荷放大电路中运算放大器的输入电压噪声是影响电路噪声的主要原因。在满足带宽的条件下,选用低噪声的运算放大器能够有效降低整个信号调理系统的噪声,从而提高系统信噪比。
For corrosion acoustic emission test,a low-noise acoustic emission signal conditioning system was designed.The system consists of a charge amplifier circuit,the voltage amplification circuit and the filter circuit.The principle of each part of the circuit is described,and the level of circuit noise is analyzed.The theoretical analysis and experiments show that the op amp input voltage noise of charge amplifier circuit is the main reason that affects the whole circuit noise.In the condition of bandwidth being met,the selection of low-noise op amp can effectively reduce the noise of the signal conditioning system and improve the system's signal-to-noise ratio.