公开(公告)号：US3982425A

公开(公告)日：1976-09-28

申请号：US433036

申请日：1974-01-14

申请人： Robert E. McLain

发明人： Robert E. McLain

IPC分类号： G01N29/44 ,  B06B1/02 ,  G01N29/04 ,  G01N29/22 ,  G01S7/52 ,  G21C17/003 ,  G01N29/00

CPC分类号： B06B1/0215 ,  G01N29/22 ,  G01S7/52046 ,  G21C17/003 ,  Y10S367/903

摘要： An ultrasonic inspection system is disclosed having a skate remotely controlled from a main console for positioning an ultrasonic transducer. A transmission line is used to couple drive pulses from the main control console to the transducer. Each drive pulse is generated at the console by timing means for firing a first silicon-controlled rectifier (SCR) to discharge a precharged capacitor into the line, and for firing a second SCR to shunt discharge current from the capacitor to ground. The line is terminated at its input end by its characteristic impedance. The length of the line may be changed without requiring any change at the transducer or the pulse generating circuit, except that the size of the precharged capacitor may be varied to assure delivery of a pulse of desired amplitude to the transducer.

摘要翻译： 公开了一种超声波检查系统，其具有从用于定位超声换能器的主控制台远程控制的滑冰板。 传输线用于将来自主控制台的驱动脉冲耦合到换能器。 每个驱动脉冲在控制台处通过用于点火第一可硅可控整流器（SCR）的定时装置产生，以将预充电的电容器放电到线路中，并且用于点火第二SCR以将放电电流从电容器分流到地。 线路的输入端由于其特性阻抗而终止。 除了可以改变预充电电容器的尺寸以确保向换能器传送所需幅度的脉冲之外，可以改变线的长度而不需要换能器或脉冲发生电路的任何改变。

公开(公告)号：US4462082A

公开(公告)日：1984-07-24

申请号：US303230

申请日：1981-09-17

申请人： Alfred W. Thiele ,  Robert E. McLain ,  Modesto T. Martinez, Jr. ,  Richard C. Lewis ,  Michael S. Kim

发明人： Alfred W. Thiele ,  Robert E. McLain ,  Modesto T. Martinez, Jr. ,  Richard C. Lewis ,  Michael S. Kim

IPC分类号： G01N29/30 ,  G01N29/04

CPC分类号： G01N29/30 ,  G01N29/4463

摘要： A method and apparatus is disclosed for calibrating an ultrasonic inspection system having a plurality of transducers (12a, 12b, 12c) coupled by a common amplifier (16) to a distance-amplitude correction (D-AC) circuit comprised of a multiplying digital-to-analog converter (26') which receives, as a function of the transit time of an ultrasonic signal measured by a clock counter (34), a D-AC correction stored in a look-up table in a random access memory (24'). The D-AC correction function stored in the look-up table for each transducer is the inverse of a return signal response curve determined by measuring the peak amplitude of return signals from calibration holes at known depths in a test block (10) while in a calibrate mode, i.e., with a switch (SW) in a state to bypass the MDAC. An equation of a curve that best fits the peak measurements is then found by a digital computer (20) and used to determine the values of points along a curve superimposed on the response curve, except at near field where the calibration system is provided with truncation for near-field effects. Inverse values of these points are then stored in the look-up table for use as correction factors applied to the amplitudes of return signals during an inspection mode of operation. In that way, all return signals from flaws of the same size are caused to have the same amplitude regardless of depth, without the need for utilizing tedious and time-consuming manual calibration methods.

摘要翻译： 公开了一种用于校准具有由公共放大器（16）耦合到距离振幅校正（D-AC）电路的多个换能器（12a，12b，12c）的超声波检查系统的方法和装置，所述距离振幅校正（D-AC）电路包括乘法数字 - 模拟转换器（26'），其接收存储在随机存取存储器（24）中的查找表中的由时钟计数器（34）测量的超声波信号的传播时间的函数的函数 '）。 存储在每个换能器的查找表中的D-AC校正函数是通过测量在测试块（10）中的已知深度处的校准孔的返回信号的峰值振幅而确定的返回信号响应曲线的倒数， 校准模式，即开关（SW）处于绕过MDAC的状态。 然后由数字计算机（20）找到最适合峰值测量的曲线方程，并用于确定沿着叠加在响应曲线上的曲线上的点的值，除了校准系统提供截断的近场 用于近场效应。 然后将这些点的逆值存储在查找表中，以用作在检查操作模式期间应用于返回信号幅度的校正因子。 以这种方式，不管深度如何，所有来自相同尺寸的瑕疵的返回信号都将具有相同的幅度，而不需要使用繁琐而耗时的手动校准方法。