1.1 本规程通常用于焊接钢球（瓶）的定期检查和测试，即声发射（AE）方法。AE用于代替静水压体积膨胀试验。通过声发射测试对瓶子进行定期检查和测试，不会像流体静力体积膨胀测试所要求的那样减压或污染。 1.2 通过在为此目的设计的工业烘箱中加热瓶子来实现所需的测试加压。达到AE测试压力所需的最高温度为 ≤ 250°F（121°C）。 1.3 在热加压过程中，使用多个传感器对瓶子进行声发射监测。 1.4 本规程是为定期检查和测试含有哈龙（UN 1044）的压力容器而制定的，哈龙通常在商用飞机上用于灭火。在商用飞机上，这些瓶子通过在加注口焊接密封。出口由爆炸激活的爆破片打开。这些压力容器在运输中的使用受美国运输部（DOT）联邦法规CFR的管制 49.DOT特别许可证授权使用声发射测试进行定期检查和测试，以代替体积膨胀和目视检查。 这些瓶子是球形的，直径从5英寸到16英寸不等。（127至406毫米）。 1.5 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。 1.6 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和健康实践，并确定监管限制的适用性。 第节给出了具体的预防说明 8. . 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 出于安全考虑，监管机构（例如美国运输部）要求对商用航空中使用的压力容器进行定期测试。 （参见第节 49，联邦法规）。声发射试验已被公认为普通静水压试验的替代方法。 5.2 在普通水压试验后的一年内不应进行声发射试验。看见 注1 . 注1: 凯撒效应与声发射的不可逆性有关，声发射在第二次加压期间导致发射减少。普通水压试验使用相对较高的试验压力（200 % 正常工作压力）。（见《联邦法规》第49节。）如果在静水压后过快进行声发射试验，则声发射结果将在低于先前最大试验压力的情况下不敏感。 5.3 当材料中的应力水平增加导致材料中的裂纹扩展或腐蚀表面中的应力相关效应（例如，金属微晶中或之间的裂纹扩展或氧化物和其他腐蚀产物的剥落和开裂）时，会产生声发射。 5.4 虽然背景噪声可能会扭曲声发射数据或使其无效，但在工业炉内加热容器几乎是一种无噪声的加压方法。此外，使用过度确定的数据集的源定位算法通常允许在存在其他干扰噪声源的情况下进行有效测试。 应减少或控制背景噪声，但此类噪声的突然出现不一定会使测试无效。

1.1 This practice is commonly used for periodic inspection and testing of welded steel gaseous spheres (bottles) is the acoustic emission (AE) method. AE is used in place of hydrostatic volumetric expansion testing. The periodic inspection and testing of bottles by AE testing is achieved without depressurization or contamination as is required for hydrostatic volumetric expansion testing. 1.2 The required test pressurization is achieved by heating the bottle in an industrial oven designed for this purpose. The maximum temperature needed to achieve the AE test pressure is ≤ 250°F (121°C). 1.3 AE monitoring of the bottle is performed with multiple sensors during the thermal pressurization. 1.4 This practice was developed for periodic inspection and testing of pressure vessels containing Halon (UN 1044), which is commonly used aboard commercial aircraft for fire suppression. In commercial aircraft, these bottles are hermetically sealed by welding in the fill port. Exit ports are opened by explosively activated burst disks. The usage of these pressure vessels in transportation is regulated under US Department of Transportation (DOT), Code of Federal Regulations CFR 49. A DOT special permit authorizes the use of AE testing for periodic inspection and testing in place of volumetric expansion and visual inspection. These bottles are spherical with diameters ranging from 5 to 16 in. (127 to 406 mm). 1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8 . 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 Because of safety considerations, regulatory agencies (for example, U.S. Department of Transportation) require periodic tests of pressurized vessels used in commercial aviation. (see Section 49, Code of Federal Regulations). AE testing has become accepted as an alternative to the common hydrostatic proof test. 5.2 An AE test should not be conducted for a period of one year after a common hydrostatic test. See Note 1 . Note 1: The Kaiser effect relates to the irreversibility of acoustic emission which results in decreased emission during a second pressurization. Common hydrostatic tests use a relatively high test pressure (200 % of normal service pressure). (See Section 49, Code of Federal Regulations.) If an AE test is performed too soon after such a hydrostatic pressurization, the AE results will be insensitive below the previous maximum test pressure. 5.3 Acoustic Emission is produced when an increasing stress level in a material causes crack growth in the material or stress related effects in a corroded surface (for example, crack growth in or between metal crystallites or spalling and cracking of oxides and other corrosion products). 5.4 While background noise may distort AE data or render it useless, heating the vessels inside an industrial oven is an almost noise free method of pressurization. Further, source location algorithms using over-determined data sets will often allow valid tests in the presence of otherwise interfering noise sources. Background noise should be reduced or controlled but the sudden occurrence of such noise does not necessarily invalidate a test.