Abstract Electret ion chambers are widely used passive detectors, employed for measurements of radon activity concentration in air. These devices are made of a Teflon electret coupled to an interchangeable ion chamber. A new type of electret produced by Rad Elec Inc., named Mid-Term, is used together with the S-type (200 cm3) chamber. It is designed to be operated in an intermediate range with respect to the standard Short-Term and Long-Term electrets. This work describes the complete characterization of such device, performed according to the ISO guidelines. The characterization was carried out in the secondary standard calibration laboratory of Politecnico di Milano Italy, and with a traceable radon chamber. The coefficients and equations presented can be used by operators to assess both the radon activity concentration and the related uncertainty, with the only requirement of the knowledge of the background gamma air kerma rate of the specific measurement site and its related uncertainty.

中文翻译：

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新 S 室中期驻极体：实验表征和不确定性评估

摘要 驻极体离子室是一种广泛使用的无源探测器，用于测量空气中氡活度浓度。这些设备由与可互换离子室耦合的特氟龙驻极体制成。Rad Elec Inc. 生产的一种新型驻极体，名为 Mid-Term，与 S 型（200 cm3）室一起使用。它被设计为在标准短期和长期驻极体的中间范围内运行。这项工作描述了根据 ISO 指南执行的此类设备的完整表征。表征是在意大利米兰理工大学的二级标准校准实验室进行的，并使用可追溯的氡气室。