辐射防护仪器 连续监测气态流出物中放射性活度的设备 第2部分：含锕系元素气溶胶监测器的特定要求

[中文适用范围]： IEC 60761-2:2026 适用于旨在对排入环境的废气气溶胶进行同步、延迟或离散顺序测量的设备。该标准适用于设计用于实现以下功能的设备：测量废气中气溶胶的体积活度（Bq/m³）或排放的总气溶胶活度（Bq），或两者兼有；当气溶胶的预设体积活度或预设总排放活度超标时，触发报警信号。该设备用于在宽活度范围内进行测量，包括在存在较大自然本底的情况下测量极微量活度。222Rn（氡）和 220Rn（钍射气）的衰变子体属于天然气溶胶，是构成自然本底的一部分。本文件旨在制定具体的标准要求，包括技术特性和通用测试条件，并提供气溶胶排放监测仪可接受方法的示例。通用要求、技术特性、测试程序、辐射特性以及电气、机械、安全和环境特性等已在 IEC 60761-1 中规定。除非另有说明，这些要求同样适用于本文件。本国际标准应与 IEC 60761-1:2002 配合使用。本第三版取消并替代了 2002 年发布的第二版。本版相较于上一版包含以下重要技术变更：增加了更精确的空气流量测试项目，包括采样体积准确性及流速鲁棒性；参考响应测试中已考虑不确定度；新增针对气溶胶粒度变化的测试；统一了所有环境、电磁及机械测试的功能性测试方法，并对各项名义平均值读数提出变异系数要求。 [外文原描述]： IEC 60761-2:2026 is applicable to equipment intended for simultaneous, delayed or discrete sequential measurement of aerosols in gaseous effluents discharged into the environment. It is applicable to equipment designed to fulfil the following functions: - the measurement of the volumetric activity (Bq/m3) of the aerosols in either gaseous effluents or the released total activity of aerosols (Bq), or both; - the actuation of an alarm signal when either a predetermined volumetric activity or a predetermined total released activity of aerosols is exceeded. This equipment is intended for measurement over a wide range of activity, including very small quantities in the presence of a much larger natural background. The daughters of 222Rn (radon) and 220Rn (thoron) are naturally occurring aerosols contributing to the natural background. The objective of this document is to establish specific standard requirements, including technical characteristics and general test conditions, and to give examples of acceptable methods for aerosol effluent monitors. The general requirements, technical characteristics, test procedures, radiation characteristics, electrical, mechanical, safety and environmental characteristics are given in IEC 60761-1. Unless otherwise stated, these requirements apply to this document. This International Standard is to be used in conjunction with IEC 60761-1:2002. This third edition cancels and replaces the second edition published in 2002. This edition includes the following significant technical changes with respect to the previous edition: - more precise tests for air-flow were added: - sampled volume correctness; - flow-rate robustness; - uncertainties have been taken into account for the reference response test; - addition of tests against aerosol granulometry variation; - creating a uniform functionality test for all environmental, electromagnetic and mechanical tests and a requirement for the coefficient of variation of each nominal mean reading.