1.1 本规程涵盖计算机射线照相（CR）系统的制造特性，该系统由特定的磷光体成像板（IP）、扫描仪、软件、扫描仪操作参数和图像显示监视器组成，并与工业射线照相的指定金属屏幕相结合。 1.2 该实践定义了系统测试，用于表征不同供应商的系统，并使其对用户具有可比性。 1.3 本规程旨在供CR系统制造商或认证机构使用，为无损检测（NDT）用户或买方消费提供CR系统特性的定量结果。其中一些测试需要专门的测试模型，以确保供应商或制造商之间的结果一致。 这些测试不供用户完成，也不用于长期稳定性跟踪和寿命测量。然而，如果需要，它们也可以用于此目的。实践 E2445 描述了旨在供用户观察CR性能和测试长期稳定性的测试。 1.4 CR系统的性能由基本的空间分辨率、对比度、信号和噪声参数以及等效透度计灵敏度（EPS）来描述。其中一些参数用于与DDA表征和薄膜表征数据进行比较（参见实施规程 E2597 和试验方法 E1815 ). 注1: 对于膜系统表征，信号由2的光密度（在雾和基底之上）和作为粒度的噪声来表示。 信噪比通过系统的孔径（类似于基本空间分辨率）进行归一化，并且是表征的一部分。该标准化通过微光度计100µm的扫描圆形孔径给出，该孔径在试验方法中定义 E1815 用于薄膜系统表征。 1.5 在这种实践中，CR系统的测量仅限于选定的辐射质量，以简化程序。CR系统的性能会随着辐射能量的变化而变化，但不会随着CR系统性能的排名而变化。如果需要，本规程的用户可以在不同或额外的辐射质量（X射线或伽马射线）下进行测试。 1.6 SI中规定的值应视为标准。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 影响CR图像质量的因素有几个，包括IP系统的基本空间分辨率、几何不清晰度、散射和对比敏感度。 有几个额外的因素（例如，软件和扫描参数）会影响使用光学扫描仪准确读取曝光IP上的图像。 4.2 该实践将用于在归一化SNR、插值基本空间探测器分辨率和EPS的基础上，通过性能水平建立CR系统的特征。本规程中的CR系统性能水平不涉及任何特定制造商的成像板。CR系统的性能水平由特定成像板的使用以及曝光条件、标准体模、扫描仪类型、软件和扫描参数产生。该表征系统提供了一种比较不同CR技术的方法，这是胶片系统的常见做法，它引导用户选择适合当前应用的配置、IP和技术。 由于空间分辨率和散射灵敏度的差异，所选择的性能水平可能与相应胶片类别的成像性能不匹配。因此，用户应始终使用像质计来证明对比度灵敏度和基本空间分辨率。 4.3 测量的性能参数显示在特性图表中。这使得用户能够通过不同的表征数据来选择特定的CR系统，以找到适合其特定应用的最佳系统。 4.4 质量因素可以通过本实践中描述的测试最准确地确定。一些系统测试需要特殊工具，而用户实验室可能无法提供这些工具。 实践中描述了更简单的质量保证和长期稳定性测试 E2445 . 4.5 工业CR系统的制造商或认证机构将使用此做法。工业CR系统的用户可以使用实践 E2445 或者执行本实践中概述的一些所述测试和测量，前提是使用所需的测试设备并严格遵守方法。如果向适当的认可工程组织证明与本规程的方法等效，则可以采用任何替代方法或辐射质量。 4.6 CR系统性能水平的公布将使指定机构和缔约方能够就特定的系统性能水平达成一致，作为确定系统适当设置或选择系统的第一步。 应通过使用实践来确认必要的图像质量 E2033 .

1.1 This practice covers the manufacturing characterization of computed radiography (CR) systems, consisting of a particular phosphor imaging plate (IP), scanner, software, scanner operational parameters, and an image display monitor, in combination with specified metal screens for industrial radiography. 1.2 The practice defines system tests to be used to characterize the systems of different suppliers and make them comparable for users. 1.3 This practice is intended for use by manufacturers of CR systems or certification agencies to provide quantitative results of CR system characteristics for nondestructive testing (NDT) user or purchaser consumption. Some of these tests require specialized test phantoms to ensure consistency of results among suppliers or manufacturers. These tests are not intended for users to complete, nor are they intended for long term stability tracking and lifetime measurements. However, they may be used for this purpose, if so desired. Practice E2445 describes tests which are intended for users to observe the CR performance and test the long term stability. 1.4 The CR system performance is described by the basic spatial resolution, contrast, signal and noise parameters, and the equivalent penetrameter sensitivity (EPS). Some of these parameters are used to compare with DDA characterization and film characterization data (see Practice E2597 and Test Method E1815 ). Note 1: For film system characterization, the signal is represented by the optical density of 2 (above fog and base) and the noise as granularity. The signal-to-noise ratio is normalized by the aperture (similar to the basic spatial resolution) of the system and is part of characterization. This normalization is given by the scanning circular aperture of 100 µm of the micro-photometer, which is defined in Test Method E1815 for film system characterization. 1.5 The measurement of CR systems in this practice is restricted to a selected radiation quality to simplify the procedure. The properties of CR systems will change with radiation energy but not the ranking of CR system performance. Users of this practice may carry out the tests at different or additional radiation qualities (X-ray or gamma ray) if required. 1.6 The values stated in SI are to be regarded as the standard. 1.7 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. 1.8 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 There are several factors affecting the quality of a CR image including the basic spatial resolution of the IP system, geometrical unsharpness, scatter, and contrast sensitivity. There are several additional factors (for example, software and scanning parameters) that affect the accurate reading of images on exposed IPs using an optical scanner. 4.2 This practice is to be used to establish a characterization of CR system by performance levels on the basis of a normalized SNR, interpolated basic spatial detector resolution and EPS. The CR system performance levels in this practice do not refer to any particular manufacturers’ imaging plates. A CR system performance level results from the use of a particular imaging plate together with the exposure conditions, standardized phantom, the scanner type, and software and the scanning parameters. This characterization system provides a means to compare differing CR technologies, as is common practice with film systems, which guides the user to the appropriate configuration, IP, and technique for the application at hand. The performance level selected may not match the imaging performance of a corresponding film class because of the difference in the spatial resolution and scatter sensitivity. Therefore, the user should always use IQIs for proof of contrast sensitivity and basic spatial resolution. 4.3 The measured performance parameters are presented in a characterization chart. This enables users to select specific CR systems by the different characterization data to find the best system for his specific application. 4.4 The quality factors can be determined most accurately by the tests described in this practice. Some of the system tests require special tools, which may not be available in user laboratories. Simpler tests are described for quality assurance and long term stability tests in Practice E2445 . 4.5 Manufacturers of industrial CR systems or certification agencies will use this practice. Users of industrial CR systems may use Practice E2445 or perform some of the described tests and measurements outlined in this practice, provided that the required test equipment is used and the methodology is strictly followed. Any alternative methods or radiation qualities may be applied if equivalence to the methods of this practice is proven to the appropriate cognizant engineering organization. 4.6 The publication of CR system performance levels will enable specifying bodies and contracting parties to agree to particular system performance level, as a first step in arriving at the appropriate settings of a system, or the selection of a system. Confirmation of necessary image quality shall be achieved by using Practice E2033 .