1.1本规程概述了X射线（韧致辐射）辐射器的安装鉴定程序以及在操作鉴定、性能鉴定和常规处理过程中应遵循的剂量学程序，以确保整个产品已在预定的吸收剂量范围内处理。还讨论了可能影响产品吸收剂量的与操作鉴定、性能鉴定和常规处理有关的其他程序。有关X射线有效或监管剂量限制和能量限制的信息不在本规程的范围内。 1.2与单能伽马辐射相比，韧致辐射能谱从低值（约35 keV）扩展到入射到X射线靶上的电子的最大能量（见第和节）。 1.3剂量测定只是辐照设施全面质量保证计划的一个组成部分。特定应用可能需要除剂量测定外的其他控制，如医疗器械灭菌和食品保存。 1.4对于食品的辐照和保健品的辐射灭菌，还存在其他特定的ISO标准。关于食品辐照，见ISO/ASTM规程51431。 保健品的辐射灭菌见ISO 11137。在ISO/ASTM规程51431或ISO 11137涵盖的领域，这些标准优先。 注1 有关特定剂量计的选择、校准和使用以及从剂量测量中解释产品中吸收剂量的指南，请参阅第节中列出的文件。 注释2 韧致辐射特性类似于放射性核素的γ辐射。有关剂量测定在γ辐照设施的特性和操作中的应用，请参阅ISO/ASTM规程51204和51702。 有关电子束辐照技术和剂量测定的信息，请参阅ISO/ASTM规程51431和51649。 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。 ====意义和用途====== 4.1各种产品和材料可进行X射线辐照，以改变其特性，提高经济价值或用于健康相关目的。示例为单个- 使用医疗器械（灭菌）、农产品（保存）和各种聚合物产品（材料改性）。X射线处理的剂量测定要求可能因产品的类型和最终用途而异。 4.2剂量计用于监测辐射过程。 注3:受管制的辐照过程需要剂量测定，例如医疗器械的灭菌和食品的保存，因为结果可能会影响消费者的健康。对于其他工业过程，例如聚合物改性，它不那么重要，可以通过辐照材料物理性质的变化来评估。 然而，常规剂量测定可用于监测治疗过程的再现性。 注4-有必要指定吸收辐射的材料。为此，通常选择水作为参考材料。水是一种使用方便的介质，因为它的辐射吸收和散射特性接近组织，并且普遍可用和理解。组织等效性的要求历史上起源于放射治疗应用。根据ISO/ASTM指南51261，可通过应用转换系数来确定除水以外的材料中的吸收剂量。 4.3辐射处理规范通常包括一对吸收剂量限值:确保预期有益效果的最小值和避免产品降解的最大值。对于给定的应用，这些值中的一个或两个可以由工艺规范或法规规定。了解辐照材料内的剂量分布对于满足这些要求至关重要。 4.4必须控制几个关键参数，以获得加工材料中的可再现剂量分布。处理速率和剂量分布取决于X射线强度、光子能谱、辐射场的空间分布、输送机速度和产品配置（见第5、8节和附录A1）。 4.5辐照过程必须合格，以确定其在交付已知可控剂量方面的有效性。这包括测试工艺设备、校准测量仪器和剂量测定系统，以及证明工艺以可靠和可再现的方式传递剂量分布的能力（见第9节和第10节）。 4.6为了确保合格辐照过程中的剂量传递一致，常规过程控制需要常规产品剂量测定、治疗前后的产品处理、辐照过程中产品的规定方向、关键过程参数的监测以及所需活动和功能的文件记录程序（见第11节和第12节）。

1.1 This practice outlines the installation qualification program for an X-ray (bremsstrahlung) irradiator and the dosimetric procedures to be followed during operational qualification, performance qualification and routine processing to ensure that the entire product has been treated within a predetermined range of absorbed dose. Other procedures related to operational qualification, performance qualification and routine processing that may influence absorbed dose in the product are also discussed. Information about effective or regulatory dose limits and energy limits for X-radiation is not within the scope of this practice. 1.2 In contrast to monoenergetic gamma radiation, the bremsstrahlung energy spectrum extends from low values (about 35 keV) up to the maximum energy of the electrons incident on the X-ray target (see Section and ). 1.3 Dosimetry is only one component of a total quality assurance program for an irradiation facility. Other controls besides dosimetry may be required for specific applications, such as medical device sterilization and food preservation. 1.4 For the irradiation of food and the radiation sterilization of health care products, other specific ISO standards exist. For food irradiation, see ISO/ASTM Practice 51431. For the radiation sterilization of health care products, see ISO 11137. In those areas covered by ISO/ASTM Practice 51431 or ISO 11137, those standards take precedence. Note 1 For guidance in the selection, calibration, and use of specific dosimeters and interpretation of absorbed dose in the product from dose measurements, see the documents listed in Section. Note 2 Bremsstrahlung characteristics are similar to those of gamma radiation from radioactive nuclides. See ISO/ASTM Practices 51204 and 51702 for the applications of dosimetry in the characterization and operation of gamma irradiation facilities. For information concerning electron beam irradiation technology and dosimetry, see ISO/ASTM Practices 51431 and 51649. 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. ====== Significance And Use ====== 4.1 A variety of products and materials may be irradiated with X-radiation to modify their characteristics and improve the economic value or for health-related purposes. Examples are single-use medical devices (sterilization), agricultural commodities (preservation), and various polymeric products (material modification). Dosimetry requirements for X-ray processing may vary depending on the type and end use of the product. 4.2 Dosimeters are used as means of monitoring the radiation process. NOTE 3 - Dosimetry is required for regulated irradiation processes, such as the sterilization of medical devices and the preservation of food, because the results may affect the health of the consumer. It is less important for other industrial processes, such as polymer modification, which can be evaluated by changes in the physical properties of the irradiated materials. Nevertheless, routine dosimetry may be used to monitor the reproducibility of the treatment process. NOTE 4 - It is necessary to specify the material in which radiation is absorbed. Frequently, water is selected as the reference material for this purpose. Water is a convenient medium to use because its radiation absorption and scattering properties are close to those of tissue and it is universally available and understood. The requirement of tissueequivalency historically originated from radiation therapy applications. Absorbed dose in materials other than water may be determined by applying conversion factors in accordance with ISO/ASTM Guide 51261. 4.3 Radiation processing specifications usually include a pair of absorbed-dose limits: a minimum value to ensure the intended beneficial effect and a maximum value to avoid product degradation. For a given application, one or both of these values may be prescribed by process specifications or regulations. Knowledge of the dose distribution within irradiated material is essential to meet these requirements. 4.4 Several critical parameters must be controlled to obtain reproducible dose distributions in the processed materials. The processing rate and dose distribution depend on the X-ray intensity, photon energy spectrum, spatial distribution of the radiation field, conveyor speed, and product configuration (see Sections 5, 8, and Annex A1). 4.5 The irradiation process must be qualified to determine its effectiveness in delivering known, controllable doses. This involves testing the process equipment, calibrating the measuring instruments and dosimetry system, and demonstrating the ability of the process to deliver dose distributions in a reliable and reproducible manner (see Sections 9 and 10). 4.6 To ensure consistent dose delivery in a qualified irradiation process, routine process control requires procedures for routine product dosimetry, product handling before and after the treatment, prescribed orientation of the products during irradiation, monitoring of critical process parameters, and documentation of the required activities and functions (see Sections 11 and 12).