1.1 本规程规定了使用锥形束系统对部件进行计算机断层扫描（CT）检查的最低要求。本规程旨在制定指示、程序和设备鉴定，以检查部件是否存在规定的不连续性。 1.2 本规程适用于具有数字检测器阵列（DDA）和X射线源的系统。它不包括同位素源的使用。 1.3 本规程中的某些章节可能需要买方和供应商之间的协议，或认可的工程组织（CEO）的具体指示。 这些项目应在采购订单或合同中说明。通常，这些项是特定于应用程序的、与性能相关的或两者都有。 1.4 锥形束CT的应用多种多样。这种做法并非旨在限制或限制。请参阅指南 第1441页 有关CT基础知识和指南的指导 第1672页 以在CT系统的选择中进行权衡。 1.5 单位- 以国际单位制表示的值应视为标准值。本标准不包括其他测量单位。 1.6 本标准并非旨在解决与其使用相关的所有安全问题。 本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 NCRP 144或NIST手册114或两者可作为指南，以确保执行射线照相程序，使人员不会受到超过城市、州或国家规范允许的最大辐射剂量。 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《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 本规程旨在制定指示、程序和设备鉴定，以检查部件是否存在规定的不连续性。编写本规程的目的是为了在工程图纸、规范或合同中明确规定。本规程要求详细的程序描述技术或程序要求，并应获得认可工程组织（CEO）的批准。 4.2 当将CT系统投入无损检测服务并建立系统性能测量基线时，应使用本规程中的要求。 应随时间监控系统性能，包括探测器校正程序、性能测量和系统维护。 4.3 对于指定不连续性未知/识别/要求/可用的CT检查（即工程分析、工程信息） 7 – 9 要求不一定适用。对于这些类型的检查，采购订单或合同应规定特定程序的制定，并经买方和供应商批准，以规定将纳入检查的本规程要求。

1.1 This practice establishes the minimum requirements for computed tomography (CT) examination of components using cone beam systems. The purpose of this practice is to establish instruction, procedures, and equipment qualification to inspect a component for specified discontinuities. 1.2 This practice applies to systems with a Digital Detector Array (DDA) and an X-ray source. It does not cover the use of isotope sources. 1.3 There are sections in this practice that may require agreement between the purchaser and the supplier, or specific direction from the cognizant engineering organization (CEO). These items should be addressed in the purchase order or the contract. Generally, the items are application-specific, performance related, or both. 1.4 Applications for cone-beam CT are diverse. This practice is not intended to be limiting or restrictive. Refer to Guide E1441 for guidance on CT fundamentals and Guide E1672 for tradeoffs in selection of a CT system. 1.5 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns 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. NCRP 144 or NIST Handbook 114, or both, may be used as guides to ensure that radiographic procedures are performed so that personnel shall not receive a radiation dosage exceeding the maximum permitted by the city, state, or national codes. 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 ====== 4.1 The purpose of this practice is to establish instruction, procedures, and equipment qualification to inspect a component for specified discontinuities. This practice is written so it can be specified on the engineering drawing, specification, or contract. This practice requires a detailed procedure delineating the technique or procedure requirements and shall be approved by the Cognizant Engineering Organization (CEO). 4.2 The requirements in this practice shall be used when placing a CT system into NDT service and establishing a baseline of system performance measures. Monitoring the system performance over time shall be performed, including detector correction procedures, performance measurements, and system maintenance. 4.3 For CT examinations where specified discontinuities are not known/identified/requested/available (that is, engineering analysis, engineering information only), portions of Section 7 – 9 requirements do not necessarily apply. For these types of examinations, the purchase order or contract shall specify the development of a specific procedure, approved by purchaser and supplier, to specify the requirements of this practice to be incorporated into the examination.