超声波探伤幻灯片-英文对照.pptVIP

The Basics Principles of Ultrasonic Inspection超声波检测的基本原则 The Basics Principles of Ultrasonic Inspection * The ultrasonic testing principle is based on the fact that solid materials are good conductors of sound waves. 超声波检测基于固体材料是声波的良好导体的事实。 Sound waves entering a test piece are reflected by the test piece interfaces and also by internal flaws (material separations, inclusions etc.). 声波进入检测物体时，会被其表面反射回来，同样也会被其内部的裂缝反射回来（材料间隔、内含物等） Ultrasonic testing may be used for 超声波检测可以用于 Detection of reflectors 反射体的探测 Locating of reflectors 反射体的定位 Evaluation of reflectors 反射体的评估 Diagnosis Diagnosis of reflectors (reflector type, orientation, etc.) 反射体的诊断 （反射体的类型、定位等） The interaction effect of sound waves with the material becomes stronger the smaller the wave length, this means the higher the frequency of the wave.材料中音波相互作用产生的效果是形成比较强、比较小的波长, 这意味更高地波频。 This ultrasonic waves used for testing are typically in a frequency range of between about 0.5 MHz and 25 MHz. 用于检测的典型超声波的频率范围在大约0.5个百万赫兹——25个百万赫兹之间。 The Ultrasonic Flaw Detector – Principles of Operation 超声波裂纹探测器——操作规则 The time measurement starts with the electrical transmission pulse, the initial pulse. This is an extremely short electrical discharge which triggers a sound pulse at the probe crystal.测量与电流传输脉冲（初始脉冲）一起开始。 这种非常短的电的释放会导致水晶探针上产生一个声脉冲 。 This pulse travels through the material and is reflected by a discontinuity or the opposing wall (back wall) and returns back to the probe。脉冲穿过材料，被一个不连续的或对立的墙反射，回到探头。 The received oscillations are converted into an electrical pulse which stops the time measurement. 接收到的振动被转换成电的脉冲，使测量时间停止。 The distance to the reflector can now be instantly determined by the following formula:通过下面的公式能够立即测算出到反射体的距离： The Ultrasonic Flaw Detector – Principles of Operation The velocity of sound (c) varies in different materials. The velocity of sound in each material must therefore be known or determined before accurate measurements can be made.声音 (c) 的速度在不同的材料中会发生改变。因此在进行精确的测量之前，必须知道每种材料中的声