利用开环方式测量氡析出率,不需要考虑泄漏和反扩散的影响,计算简单。但是开环方式测量氡析出率测量中有一个很重要的参数是泵的流率,对于高析出率介质,采用较高的流率,可以减小集氡罩内氡浓度达到恒定的时间,提高测量效率;对于低析出率介质,采用较高的流率,会导致集氡罩内的氡浓度值偏低,统计涨落较大,甚至会使得集氡罩内的氡浓度值难以测量。首先将泵的流率调至较低,利用前几个测量周期的测量数据,自动得到氡析出率的近似值,再自适应地调节气泵的流率大小,最终较准确地测量得到氡析出率。
The calculation of measuring radon exhalation rate in open-loop is simple,without considering the effects of leakage and back-diffusion.But the pump flow rate is a very important parameter in the measurement.If the exhalation rate of the medium is high,the time for the radon concentration in the chamber becomes constant decrease while the pump flow rate is high.The measurement efficiency will be improved.If the exhalation rate of the medium is low,the radon concentration in the chamber will be very low for measuring while the pump flow rate is high,and the statistical fluctuation is large.We propose that adjust the pump flow low first,the approximate radon exhalation rate can be obtained by several measurement data,then adaptive re-regulation of the pump flow rate,and ultimately get more accurate radon exhalation rate.