公开(公告)号：US5119678A

公开(公告)日：1992-06-09

申请号：US456992

申请日：1989-12-26

申请人： Manohar Bashyam ,  David C. Copley

发明人： Manohar Bashyam ,  David C. Copley

IPC分类号： G01B17/02 ,  G01N29/04 ,  G01N29/06 ,  G01N29/30 ,  G01N29/32 ,  G01N29/40

CPC分类号： G01N29/40 ,  G01B17/02 ,  G01N29/0609 ,  G01N29/0645 ,  G01N29/30 ,  G01N29/32 ,  G01N2291/015 ,  G01N2291/02854 ,  G01N2291/048 ,  G01N2291/102 ,  G01N2291/269

摘要： A method for locating and identifying defects in a variable geometry workpiece using first and second transceivers positioned of a preselected distance apart adjacent opposite surfaces of the workpiece and aligned to direct ultrasonic signals toward each other through the workpiece. An ultrasound signal is transmitted from each transceiver toward the workpiece. Signal reflections from each adjacent workpiece surface are detected and used to compute workpiece thickness. Signals from one transceiver are detected at the other transceiver and their intensity determined. The signal intensity is normalized in proportion to the obtained workpiece thickness to establish a signal intensity independent of workpiece thickness. In one form, at least three signal processing paths, each having a different preselected gain, provide three signals of different amplified intensities for each measurement point. The one of the signals having the greatest amplitude not exceeding an established maximum processable signal intensity is selected and the actual intensity of the signal passing through the workpiece is computed by correlating the amplitude of the selected one of the three signals with the gain of the channel from which the signal is selected. A signal intensity corresponding to the actual intensity is displayed on an intensity responsive display for each measurement point after the actual intensity is adjusted for workpiece thickness.

摘要翻译： 一种用于使用第一和第二收发器来定位和识别可变几何工件中的缺陷的方法，所述第一和第二收发器定位在工件的相邻相对表面之间的预选距离处，并且对齐以将超声波信号通过工件彼此引导。 从每个收发器向工件发送超声信号。 检测来自每个相邻工件表面的信号反射并用于计算工件厚度。 在另一个收发器处检测来自一个收发器的信号，并确定它们的强度。 信号强度与获得的工件厚度成正比，以建立独立于工件厚度的信号强度。 在一种形式中，每个具有不同预选增益的至少三个信号处理路径为每个测量点提供不同放大强度的三个信号。 选择具有最大幅度的信号幅度不超过建立的最大可处理信号强度的信号之一，并且通过将三个信号中所选择的一个信号的幅度与信道的增益相关联来计算通过工件的信号的实际强度 从中选择信号。 在对工件厚度进行实际强度调整后，在每个测量点的强度响应显示上显示对应于实际强度的信号强度。