1.1 本规程涵盖了用于评估与超声波检测仪器一起使用的超声波搜索装置（也称为“探头”）某些特性的测量程序。本规程描述了获取性能数据的方法，这些数据可用于定义超声波搜索装置的声响应和电响应。 1.2 这些程序旨在使用商业搜索单元表征系统或实验室仪器（如信号发生器、脉冲发生器、放大器、数字化仪、示波器和波形分析仪）将搜索单元作为单个组件进行测量（与超声波测试仪器分离）。 1.3 本程序适用于新搜索装置的制造验收和进货检验，或搜索装置在其整个使用寿命内的定期性能评估。 1.4 中的程序 附件A1– 附录A6 通常适用于在0.4至10 MHz范围内工作的超声波搜索装置。 附件A7 适用于高频浸入式搜索单元评估。 附录A8 描述了从接触直束搜索装置测量金属中声束轮廓的实践。附加附件，如角度的声束剖面- 开发时，将添加金属束搜索单元和搜索单元表征的替代方法。 1.5 单位- 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不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 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 本规程旨在提供评估超声搜索装置的标准程序。其目的不是定义性能和验收标准，而是提供建立此类标准的数据。 5.2 这些程序旨在评估单元件压电搜索单元的特性。 5.3 实施可能需要以使用设施的形式提供更详细的程序说明。 5.4 本规程的用户可以使用获得的测量数据来指定、描述或提供采购和质量保证的性能标准，或对超声波搜索装置的工作特性进行服务评估。 根据用户的决定，可以使用全部或部分实践。 5.5 测量主要在脉冲回波条件下进行。为了确定作为发射器或接收器的搜索单元的相对性能，可能需要额外的测试。 5.6 虽然这些程序涉及许多重要参数，但在特定应用中可能重要的其他程序可能不会得到处理。这些可能包括功率处理能力、击穿电压、接触单元的磨损特性、射频干扰等。 5.7 必须注意确保进行了可比较的测量，并且实践的用户遵循类似的程序。指定或选择的条件（如果可选）可能会影响测试结果并导致明显差异。 5.8 一些测试结果的解释，如频率响应曲线的形状，可能是主观的。小的不规则可能很严重。测试结果的解释超出了本规程的范围。 5.9 使用概述的程序获得的某些结果可能不同于使用超声波测试仪器进行的测量。 这些差异可能归因于实验性质或仪器电气特性的差异。 5.10 用于获得搜索单元的频率响应和时间响应的脉冲发生器必须具有足够的上升时间、持续时间和频谱内容，以在其整个带宽上激励搜索单元，否则可能会导致时间失真和错误结果。

1.1 This practice covers measurement procedures for evaluating certain characteristics of ultrasonic search units (also known as “probes”) that are used with ultrasonic testing instrumentation. This practice describes means for obtaining performance data that may be used to define the acoustic and electric responses of ultrasonic search units. 1.2 The procedures are designed to measure search units as individual components (separate from the ultrasonic test instrument) using commercial search unit characterization systems or using laboratory instruments such as signal generators, pulsers, amplifiers, digitizers, oscilloscopes, and waveform analyzers. 1.3 The procedures are applicable to manufacturing acceptance and incoming inspection of new search units or to periodic performance evaluation of search units throughout their service life. 1.4 The procedures in Annex A1 – Annex A6 are generally applicable to ultrasonic search units operating within the 0.4 to 10 MHz range. Annex A7 is applicable to higher frequency immersion search unit evaluation. Annex A8 describes a practice for measuring sound beam profiles in metals from contact straight-beam search units. Additional Annexes, such as sound beam profiling for angle-beam search units in metal and alternate means for search unit characterization, will be added when developed. 1.5 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 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 This practice is intended to provide standardized procedures for evaluating ultrasonic search units. It is not intended to define performance and acceptance criteria, but rather to provide data from which such criteria may be established. 5.2 These procedures are intended to evaluate the characteristics of single-element piezoelectric search units. 5.3 Implementation may require more detailed procedural instructions in a format of the using facility. 5.4 The measurement data obtained may be employed by users of this practice to specify, describe, or provide a performance criteria for procurement and quality assurance, or service evaluation of the operating characteristics of ultrasonic search units. All or portions of the practice may be used as determined by the user. 5.5 The measurements are made primarily under pulse-echo conditions. To determine the relative performance of a search unit as either a transmitter or a receiver may require additional tests. 5.6 While these procedures relate to many of the significant parameters, others that may be important in specific applications may not be treated. These might include power handling capability, breakdown voltage, wear properties of contact units, radio-frequency interference, and the like. 5.7 Care must be taken to ensure that comparable measurements are made and that users of the practice follow similar procedures. The conditions specified or selected (if optional) may affect the test results and lead to apparent differences. 5.8 Interpretation of some test results, such as the shape of the frequency response curve, may be subjective. Small irregularities may be significant. Interpretation of the test results is beyond the scope of this practice. 5.9 Certain results obtained using the procedures outlined may differ from measurements made with ultrasonic test instruments. These differences may be attributed to differences in the nature of the experiment or the electrical characteristics of the instrumentation. 5.10 The pulse generator used to obtain the frequency response and time response of the search unit must have a rise time, duration, and spectral content sufficient to excite the search unit over its full bandwidth, otherwise time distortion and erroneous results may result.