储罐底板电-磁-声复合检测仪器的研制

Development of Composite Electro-Magnetic-Acoustic Detection Instrument for Tank Bottom Plate

针对储罐底板在役检测过程中遇到的难题,研制可以实现漏磁、电磁超声、导波和脉冲涡流4种检测方法的复合检测仪器。提出结合继电器和电源稳压模块的电源供电方案,解决复合仪器研制相关的硬件电路中多电平、多频率复合时所引入的串扰问题。其中复合仪器的电磁超声测厚采用基于阈值电平的脉冲计数法全硬件实现厚度测量,需要对部分硬件参数进行调节,开发基于现场可编程逻辑门阵列和数字电位器的程控调节方案,使增益、阈值、时延等电路参数可以实时调节从而实现基于阈值电平脉冲计数法的电磁超声测厚。最后,在室内实验平台上对系统的检测性能进行了测试,结果表明:电-磁-声复合检测仪器可以实现导波、漏磁、电磁超声以及脉冲涡流检测,各检测模块工作正常。

Aiming at the difficulties in detecting storage tank’s bottom plate,a composite detection instrument which boasts of testing magnetic flux leakage,electromagnetic ultrasound,guided wave and pulsed eddy current was developed and a power control scheme which combining relay and power regulator module was proposed to solve the interference introduced by multi-level and multi-frequency composition in hardware circuits related to composite sensing technology.In which,the composite instrument has a pulse counting method which based on the threshold level adopted to realize electromagnetic ultrasonic thickness measurement,and having some hardware parameters adjusted to develop a program control adjustment scheme based on the field programmable logic gate array and digital potentiometer so as to regulate the gain,threshold,time delay and other circuit parameters in real time,including to realize the electromagnetic ultrasonic thickness measurement based on the threshold level pulse counting method.Testing the system performance on the laboratory experimental platform shows that,the composite electromagnetic-magnetic-acoustic detection instrument can realize guided wave,magnetic leakage,electromagnetic ultrasonic and pulse eddy current detection,and the detection modules work normally.