1Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104.
Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104.
Health Phys. 2019 Jun;116(6):852-861. doi: 10.1097/HP.0000000000001047.
An unventilated 70 m underground space, with 2.1 m high ceilings and an inner set of concrete walls to damp vibrations, was discovered to have relatively stable radon levels of ~1,080 Bq m over a 1-y period. The addition of radium sources was not required to achieve high and somewhat variable radon levels, as these arise naturally in the space. Several active radon monitoring devices designed for homeowners, radon screeners, radon mitigation professionals, and researchers were tested in the space. These devices were variable in both cost and intended user sophistication. Data were collected at specific time intervals that varied for each device. A cellphone was deployed with an available camera application to periodically capture photographs of the displays of devices not enabled for automatic temporal recording. Attempts were made to alter the radon concentration using fans, radium-laden objects, and radon impermeable sheets. Statistical methods were employed to compare the device's performance under the minor radon transients produced by the addition of Ra sources during the test period. The evaluation of the overall accuracy, noise, and response to transients revealed highly affordable devices that may be useful for future research applications. While unsuitable for precise calibrations at stable radon levels, the space was determined to be adequate as a radon chamber for general research purposes.
一个未通风的 70 米地下空间，天花板高 2.1 米，内部有一圈混凝土墙来减震，在一年的时间里，发现其氡水平相对稳定，约为 1080 Bq m。不需要添加镭源来达到较高且有些变化的氡水平，因为这些氡是空间中自然产生的。一些专为房主、氡筛查器、氡缓解专业人员和研究人员设计的活性氡监测设备在该空间中进行了测试。这些设备在成本和预期用户的复杂程度上都有所不同。数据是在特定的时间间隔内收集的，每个设备的时间间隔都不同。还部署了一部带有可用摄像头应用程序的手机，以便定期拍摄未启用自动时间记录的设备显示屏的照片。曾尝试使用风扇、含镭物体和氡不透性薄片来改变氡浓度。采用统计方法比较了在测试期间添加 Ra 源产生的较小氡瞬变条件下设备的性能。对整体精度、噪声和对瞬变的响应的评估揭示了价格实惠的设备，这些设备可能对未来的研究应用有用。虽然不适合在稳定的氡水平下进行精确校准，但该空间被确定为一般研究目的的氡室是足够的。
