1.1 这种做法 2. 介绍了使用传统的脉冲回波法对材料进行超声波检查，该方法使用搜索单元与被检查材料直接接触产生的直束纵波。 1.2 本规程适用于文件用户同意的检查程序的制定。 1.3 单位- 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.4 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。 1.5 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 本规程使用正入射或直束纵波超声检测和评估需要体积检查的材料中的不连续性。 5.2 尽管并非本规程的所有要求都能普遍适用于所有检查情况和材料，但它确实为材料供应商和买方之间建立合同标准提供了基础，以进行接触纵波脉冲回波检查，并可作为编写特定应用程序详细程序的指南。 5.3 可从脉冲回波直束实践中获得的信息类型如下: 5.3.1 表观不连续尺寸（见 注1 )通过将试样的信号振幅与从参考标准获得的振幅进行比较。 5.3.2 通过校准A扫描显示器的水平比例来定位不连续的深度。 5.3.3 由比较项目的相对声衰减或速度变化表示的材料特性。 5.3.4 如果几何形状和材料允许，两种超声导电材料之间的粘结和未粘结程度（或融合和未融合）。 注1: 强调“明显”一词，因为实际尺寸取决于不连续性的方向、组成和几何形状以及设备限制。

1.1 This practice 2 covers ultrasonic examination of materials using the conventional pulse-echo method using straight-beam longitudinal waves introduced by direct contact of the search unit with the material being examined. 1.2 This practice shall be applicable to development of an examination procedure agreed upon by the users of the document. 1.3 Units— The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.4 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. 1.5 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 employs the use of normal-incident, or straight beam, longitudinal wave ultrasound for the detection and evaluation of discontinuities in materials requiring volumetric examination. 5.2 Although not all requirements of this practice can be applied universally to all inspection situations and materials, it does provide the basis for establishing contractual criteria between suppliers and purchasers of materials for performing contact longitudinal wave pulse-echo examination and may be used as a guide for writing detailed procedures for particular applications. 5.3 Types of information that may be obtained from the pulsed-echo straight-beam practice are as follows: 5.3.1 Apparent discontinuity size (see Note 1 ) by comparison of the signal amplitudes from the test piece to the amplitudes obtained from a reference standard. 5.3.2 Depth location of discontinuities by calibrating the horizontal scale of the A-scan display. 5.3.3 Material properties as indicated by the relative sound attenuation or velocity changes of compared items. 5.3.4 The extent of bond and unbond (or fusion and lack of fusion) between two ultrasonic conducting materials if geometry and materials permit. Note 1: The term “apparent” is emphasized since true size depends on orientation, composition, and geometry of the discontinuity and equipment limitations.