1.1 本规程旨在与共振超声光谱仪一起使用，共振超声光谱仪能够激励、测量、记录和分析多个全身机械振动共振频率，这些共振频率在声学或超声波或两者的共振频率范围内表现出声振铃。 1.2 本规程使用共振超声光谱学（RUS）来区分合格零件（根据合格的训练集确定）和弹性特性中包含显著异常的零件。 1.3 RUS监测系统的基本功能是检测和分类共振现象。固体结构共振由零件的尺寸、密度和弹性特性决定。当贵金属中发生材料替代时，所选金属具有几乎相同的密度和不变的尺寸，只留下弹性特性来影响共振。 1.4 本规程可用于替代破坏性方法，即通过钻孔或熔化或两者同时损坏试样。 1.5 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 从人类历史开始，货币就以金属硬币和金条的形式存在。盗贼们了解到，剃掉一些贵重金属提供了一种改变其价值的方法。用普通金属代替价值较高的贵金属是很常见的，直到称重方法变得如此准确，以至于很容易检测出来。合金也被用作替代品，直到廉价的光谱仪可用，从而结束了假冒行为。黄金价值的快速上涨激发了那些不择手段的人去寻找一种新方法。钨被广泛用于灯泡灯丝，直到法规改变了这个市场。现在可用的大量钨，加上几乎相同的金密度，提供了一个新的机会。 5.2 RUS提供了一种方法，为每个测试件创建一个独立于操作员的唯一电子签名。

1.1 This practice is intended for use with resonant ultrasound spectrometers capable of exciting, measuring, recording, and analyzing multiple whole body mechanical vibration resonant frequencies within parts exhibiting acoustical ringing in the acoustic or ultrasonic, or both, resonant frequency ranges. 1.2 This practice uses Resonant Ultrasound Spectroscopy (RUS) to distinguish conforming parts, as determined from qualified training sets, from those containing significant anomalies in their elastic properties. 1.3 The basic functions of a RUS monitoring system are to detect and classify resonance phenomena. Solid structure resonances are governed by the part’s dimensions, density, and elastic properties. When a material substitution occurs in a precious metal, the chosen metals have almost identical densities and unchanged dimensions, leaving only the elastic properties to affect the resonances. 1.4 This practice can be used to replace destructive methods, which damage the test object through drilling or melting, or both. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Since the beginning of human history, currency has existed in the form of metal coins and bullion. Thieves learned that shaving some precious metal provided a method to change its value. Substitution of common metals for precious metals of higher value was commonplace until weighing methods became so accurate, that it became easily detected. Alloys were also used as substitutes until inexpensive spectrometers became available which ended the counterfeiting practice. The rapid rise in the value of gold inspired the unscrupulous to find a new method. Tungsten was widely used for light bulb filaments until regulations changed that market. The great abundance of tungsten now available, coupled with the almost identical density of gold, presented a new opportunity. 5.2 RUS provides a method to create an unique electronic signature for each piece tested which is operator independent.