1.1 本规程描述了工业射线照相用计算机射线照相（CR）系统的评估。其目的是确保图像质量评估（受CR系统的影响）满足本标准用户及其客户的需求，并实现CR系统的过程控制和长期稳定性。 1.2 本规程规定了要测量的CR系统的基本参数，以确定基线性能，并跟踪系统的长期稳定性。这些测试适用于高达320的应用 kV。大于320时 kV或使用伽马源时，这些测试仍可用于表征系统，但可能需要根据用户和认可的工程组织（CEO）之间的约定进行修改。 1.3 本实施规程中规定的CR系统性能测试应在制造商验收系统后，按照本实施规程中规定的间隔完成，以监测系统的长期稳定性。 这些测试的目的是监测系统性能退化，并确定当系统退化到一定程度时，何时需要采取行动。 1.4 每次测试都必须使用本标准中提供的量规。如果这些测试或量规不够，用户应与首席执行官协调，开发额外或修改的测试、测试对象、量规或图像质量指示器，以评估CR系统。这些替代测试的验收水平应由用户和首席执行官之间的协议确定。 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====== 4.1 本规程旨在供无损检测使用组织用于测量CR系统的基线性能，并在其作为无损检测成像系统的整个服务过程中监测其性能。 在本文件中，CR系统定义为: 4.1.1 存储磷光体成像板（IP）类型和制造商， 4.1.2 读取装置（扫描仪或读取器）制造商和型号，包括适用的扫描仪设置（例如，采样分辨率、PMT增益、像素值（PV）查找表等）， 4.1.3 图像采集和处理软件，以及 4.1.4 图像显示监视器。 4.2 应当理解，用户已经根据手头的检查需要从制造商处选择并购买了CR系统。用户应根据制造商的实践结果接受CR扫描仪 E2446 在该系列CR扫描仪的数据表中提供的特定CR扫描仪上，或在用户和制造商之间商定的其他验收测试上（本规程未涵盖）。本实践不打算用作CR系统的“验收测试”，而是建立一个性能基线，以便在运行时进行跟踪- 服务 4.3 尽管本标准中列出的许多特性具有与实践中发现的相似的指标 E2446 ，数据收集方法不尽相同，不应对每种标准获得的值进行比较。 4.4 本规程定义了要执行的测试和所需的间隔。还定义了CR用户将在CR系统基线后完成的结果制表方法。这些测试也将按规定的要求间隔定期进行，以评估CR系统，以确定系统是否保持在本规程中规定的可接受操作范围内。 4.5 有几个因素会影响CR图像的图像质量。依赖于CR系统性能的因素包括基本空间分辨率、相对对比度和信号- 产生对比度灵敏度（CS）和等效透度计灵敏度（EPS）的信噪比（SNR）。还有几个其他因素取决于CR系统的运行情况（即正常磨损、维护不足、设置/校准不当等），例如滑动、激光抖动、几何畸变、，等。与特定应用相关的其他因素（例如，几何不清晰度、散射等）在这些测试中未进行评估。

1.1 This practice describes the evaluation of Computed Radiography (CR) systems for industrial radiography. It is intended to ensure that the evaluation of image quality, as far as this is influenced by the CR system, meets the needs of users of this standard, and their customers, and enables process control and long-term stability of the CR system. 1.2 This practice specifies the fundamental parameters of CR systems to be measured to determine baseline performance, and to track the long term stability of the system. These tests are for applications up to 320 kV. When greater than 320 kV or when a gamma source is used, these tests may still be used to characterize a system, but may need to be modified as agreed between the user and cognizant engineering organization (CEO). 1.3 The CR system performance tests specified in this practice shall be completed upon acceptance of the system from the manufacturer and at intervals specified in this practice to monitor long term stability of the system. The intent of these tests is to monitor the system performance degradation and to identify when an action needs to be taken when the system degrades by a certain level. 1.4 The use of gauges provided in this standard is mandatory for each test. In the event these tests or gauges are not sufficient, the user, in coordination with the CEO shall develop additional or modified tests, test objects, gauges, or image quality indicators to evaluate the CR system. Acceptance levels for these ALTERNATE tests shall be determined by agreement between the user and CEO. 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 ====== 4.1 This practice is intended to be used by the NDT using organization to measure baseline performance of the CR system and to monitor its performance throughout its service as an NDT imaging system. For purposes of this document, the CR System is defined as: 4.1.1 Storage phosphor imaging plate (IP) type and manufacturer, 4.1.2 Read out unit (scanner or reader) manufacturer and model, including applicable scanner settings (for example, sampling resolution, PMT gain, pixel value (PV) look up table, etc.), 4.1.3 Image acquisition and processing software, and 4.1.4 Image display monitor. 4.2 It is to be understood that the CR system has already been selected and purchased by the user from a manufacturer based on the inspection needs at hand. The user shall accept the CR scanner based on manufacturer’s results of Practice E2446 on the specific CR scanner as provided in a data sheet for that serialized CR scanner or other acceptance test agreed to between the user and manufacturer (not covered in this practice). This practice is not intended to be used as an “acceptance test” of the CR system, but rather to establish a performance baseline that will enable tracking while in-service. 4.3 Although many of the properties listed in this standard have similar metrics to those found in Practice E2446 , data collection methods are not identical, and comparisons among values acquired with each standard should not be made. 4.4 This practice defines the tests to be performed and required intervals. Also defined are the methods of tabulating results that CR users will complete following the baseline of the CR system. These tests will also be performed periodically at the stated required intervals to evaluate the CR system to determine if the system remains within acceptable operational limits as established in this practice. 4.5 There are several factors that affect the image quality of a CR image. Factors which are dependent on the CR system performance include basic spatial resolution, relative contrast, and signal-to-noise ratio (SNR) which yield the contrast sensitivity (CS) and Equivalent Penetrameter Sensitivity (EPS). There are several additional factors that are dependent on how well the CR system is functioning (that is, resulting from normal wear and tear, inadequate maintenance, improper setup/calibration, etc.), such as slippage, laser jitter, geometric distortion, etc. Other factors which are related to the specific applications (for example, geometric unsharpness, scatter, etc.) are not evaluated in these tests.