1.1 本规范涵盖了半绝热量热剂量测定系统的制备和使用，用于测量吸收剂量，以及在辐射处理应用中用电子辐照时校准常规剂量测定系统。量热计或者由传送带传送经过扫描的电子束，或者固定在加宽的电子束中。 1.2 本文件是为在辐射处理中正确实施剂量测定提供建议的一组标准之一，并描述了实现符合ASTM实践要求的方法 52628 用于量热剂量测定系统。它旨在与ASTM实践一起阅读 52628 . 1.3 根据影响量的复杂作用，本实施例中描述的量热计被归类为II型剂量计。参见ASTM实践 52628 . 1.4 本实践适用于能量范围为1.5至12兆电子伏的电子束。 1.5 吸收剂量范围取决于量热吸收材料以及照射和测量条件。最小剂量约为100 Gy，最大剂量约为50 kGy。 1.6 平均吸收剂量率范围一般应大于10Gy·s -1 . 1.7 使用这些量热剂量测定系统的温度范围取决于量热材料的热阻、温度传感器的校准范围和测量装置的灵敏度。 1.8 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。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法规限制的适用性。1.9 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 本规范适用于使用量热剂量测定系统测量电子束中的吸收剂量、电子辐照设施的鉴定、电子辐照设施运行参数的定期检查以及电子束中其他剂量测定系统的校准。量热剂量测定系统最适合于在辐照期间利用传送系统运输产品的电子辐照设施的剂量测量。附注1: 有关量热剂量测定系统操作和使用的更多信息，请参见ICRU报告80。有关在电子加速器设备中使用剂量测定的更多信息，请参见ASTM 51649 、ICRU报告34和35以及参考文献 ( 1- 3 ) . 6 4.2 本实施规程中描述的量热剂量测定系统不是主要的标准剂量测定系统。量热计被分类为II型剂量计（ASTM 52628 ).它们可以用作电子束辐照设施的内部标准，包括用作用于校准其他剂量测定系统的转移标准剂量测定系统，或者它们可以用作常规剂量计。通过与转移标准剂量计比较来校准量热剂量测定系统。 4.3 剂量测量基于对被电子束照射的吸收器(量热体)中的温度上升(剂量计响应)的测量。使用不同的吸收材料，但通常根据对水的剂量来定义响应。 附注2: 本实施例中描述的量热计的量热体由低原子序数材料制成。当用1.5 MeV或更高的电子束照射时，这些量热体内的电子注量几乎与能量无关，并且对于这些材料，质量碰撞停止功率大致相同。 4.4 可以计算在同等条件下辐照的其他材料中的吸收剂量。进行此类计算的程序在ASTM实践中给出 E666 和 E668 ，和参考 ( 1 ) . 4.4.1 已经使用石墨、聚苯乙烯或填充有水的培养皿作为量热体来构造用于工业电子加速器的量热计 ( 4- 10 ) 量热体的厚度应小于入射电子的范围。 4.4.2 除了聚苯乙烯之外的聚合物材料也可以用于量热测量。使用聚苯乙烯是因为已知它耐辐射 ( 11 ) 因为几乎不发生外热或吸热反应 ( 12 ) .

1.1 This practice covers the preparation and use of semi-adiabatic calorimetric dosimetry systems for measurement of absorbed dose and for calibration of routine dosimetry systems when irradiated with electrons for radiation processing applications. The calorimeters are either transported by a conveyor past a scanned electron beam or are stationary in a broadened beam. 1.2 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM Practice 52628 for a calorimetric dosimetry system. It is intended to be read in conjunction with ASTM Practice 52628 . 1.3 The calorimeters described in this practice are classified as Type II dosimeters on the basis of the complex effect of influence quantities. See ASTM Practice 52628 . 1.4 This practice applies to electron beams in the energy range from 1.5 to 12 MeV. 1.5 The absorbed dose range depends on the calorimetric absorbing material and the irradiation and measurement conditions. Minimum dose is approximately 100 Gy and maximum dose is approximately 50 kGy. 1.6 The average absorbed-dose rate range shall generally be greater than 10 Gy·s -1 . 1.7 The temperature range for use of these calorimetric dosimetry systems depends on the thermal resistance of the calorimetric materials, on the calibration range of the temperature sensor, and on the sensitivity of the measurement device. 1.8 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. 1.9 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 applicable to the use of calorimetric dosimetry systems for the measurement of absorbed dose in electron beams, the qualification of electron irradiation facilities, periodic checks of operating parameters of electron irradiation facilities, and calibration of other dosimetry systems in electron beams. Calorimetric dosimetry systems are most suitable for dose measurement at electron irradiation facilities utilizing conveyor systems for transport of product during irradiation. Note 1: For additional information on calorimetric dosimetry system operation and use, see ICRU Report 80. For additional information on the use of dosimetry in electron accelerator facilities, see ASTM 51649 , and ICRU Reports 34 and 35, and Refs ( 1- 3 ) . 6 4.2 The calorimetric dosimetry systems described in this practice are not primary standard dosimetry systems. The calorimeters are classified as Type II dosimeters (ASTM 52628 ). They might be used as internal standards at an electron beam irradiation facility, including being used as transfer standard dosimetry systems for calibration of other dosimetry systems, or they might be used as routine dosimeters. The calorimetric dosimetry systems are calibrated by comparison with transfer standard dosimeters. 4.3 The dose measurement is based on the measurement of the temperature rise (dosimeter response) in an absorber (calorimetric body) irradiated by an electron beam. Different absorbing materials are used, but the response is usually defined in terms of dose to water. Note 2: The calorimetric bodies of the calorimeters described in this practice are made from low atomic number materials. The electron fluences within these calorimetric bodies are almost independent of energy when irradiated with electron beams of 1.5 MeV or higher, and the mass collision stopping powers are approximately the same for these materials. 4.4 The absorbed dose in other materials irradiated under equivalent conditions can be calculated. Procedures for making such calculations are given in ASTM Practices E666 and E668 , and Ref ( 1 ) . 4.4.1 Calorimeters for use at industrial electron accelerators have been constructed using graphite, polystyrene or a Petri dish filled with water as the calorimetric body ( 4- 10 ) . The thickness of the calorimetric body should be less than the range of the incident electrons. 4.4.2 Polymeric materials other than polystyrene might also be used for calorimetric measurements. Polystyrene is used because it is known to be resistant to radiation ( 11 ) and because almost no exo- or endothermic reactions take place ( 12 ) .