便携式氡析出率自动测量仪研究

Research of Portable Automatic Measuring Monitor of Radon Exhalation Rate

氡析出率的可靠测量是环境氡污染治理中的关键因素。活性炭吸附法和静电收集法是氡析出率测量的常用方法,活性炭吸附法适合于在温湿度相对稳定且氡析出率变化不太大的条件下使用,静电收集法能实现快速测量,但目前静电收集式测氡仪如RAD7需对测量的氡浓度进行数据修正才能得到氡析出率。为实现氡析出率的可靠测量,南华大学基于累积集氡和静电收集法测氡的方式研制了一种便携式氡析出率自动测量仪,该测量仪无需干燥管干燥取样的气体,减少了干燥剂对集氡罩内介质表面氡析出率的影响。在自然环境下,该测量仪能准确测量氡浓度,无需借助计算机进行线性拟合处理数据,由内置微处理器将线性拟合转化为代数运算后便能根据测量的氡浓度自动计算出氡析出率。实验表明,该氡析出率自动测量仪在氡析出率标准装置上的测量值与参考值的相对偏差在5%以内。测量完毕直接得出氡析出率,方便了现场氡析出率测量的需求。

The reliable measurement of radon exha＇lation rate is critical in environmental radon pollution regulation. The activated carbon adsorption method and electrostatic collection method are commonly used to measure radon exhalation rate. Only when the range of radon exhalation rate variation is relatively small and environment condition is relatively stable, the activated carbon adsorption method can be applied. Although the electrostatic collection method can realize fast measurement, the present electrostatic collection type manometer such as RAD7 still needs to conduct data correction to obtain the value of radon exhalation rate. In order to achieve the reliable measurement of the radon exhalation rate, University of South China developed a portable automatic meas- uring monitor of radon exhalation rate in accordance with methods of collecting radon through accumulation and measuring radon by collecting static. This measuring monitor can sample gas without drying tube, which reduces the influence of desiccant on radon exhalation rate of dielectric surface in radon collecting cover in natural environment, and it can accurately measure the instantaneous radon concentration without needing person- al computer to conduct linear fitting and data processing. After its internal microproces- sor converts linear fitting into algebraic operation, it can automatically calculate the radon exhalation rate based on measured radon concentration. The experiment indicates that the relative deviation is less than 5%. The directly obtained radon exhalation rate after measuring satisfies the requirement of field radon exhalation rate measurement.