Comprehensive Analysis And Caculation For Measured Parameters Of The Radon Exhalation Rate On Medium Surface

Radon is a natural radioactive inert gas.Radon is one of the main sources of natural radiation to human beings.The dose caused by radon is about 50% of all natural radiation.Indoor radon mainly originates from building materials and soil,its pollution and harm has already aroused people’s special concern,the important condition of radon control is the rapid and accurate measurement of radon exhalation rate.The measurement of radon exhalation rate by electrostatic collection method can eliminate the interference of leakage,reverse diffusion and background of environmental radon,and it can measure the radon exhalation rate quickly and reliably,which has important application value.The effect of radon collection parameters and sampling methods on open-loop radon exhalation rate measurement based on electrostatic collection was studied.The effects of radon collection opening mode,volume bottom area and sampling method on the measurement of radon exhalation rate are obtained,as well as the suitable airflow rate and measuring period for the reference device of radon exhalation rate with different concentrations.In this paper,the influence of radon collection parameters on the radon exhalation rate of closed-loop measurement is simulated and analyzed,and the influence of measurement parameters(sampling time,radon chamber parameter,air flow rate,etc.)on the measurement of radon exhalation rate by two-chamber equilibrium method is considered synthetically and optimally.The optimal calculation model of measurement parameters by two-chamber balance method is established.Based on the optimized model,a program for optimizing the measurement parameters of radon exhalation rate is designed by using Lab VIEW,and the optimization program is debugged and applied experimentally.The test results show that the open loop and closed loop measurement method of the interface of the optimization program can be chosen according to the user’s measurement parameters,and the optimal measurement parameters are given,which is convenient for the user under different measuring conditions.The reasonable selection of sampling time,radon chamber parameters and airflow rate in the measurement parameters.In the closed-loop measurement,the program user interface can control the working state of the NRL-Ⅱcontinuous radon measuring instrument,and read and save the instrument measurement data as the file of.csv.The radon exhalation rate is calculated by introducing the program interface,and the radon exhalation rate of the measured medium is measured and calculated quickly.The experimental application shows that the measurement of the reference standard device for the middle concentration radon exhalation rate,the open loop type and the closed loop type in the optimization system can be used to measure the optimized measurement parameters well,and the error range of the reference value is small.Radon exhalation rate can be measured quickly and reliably.In the closed-loop experiment,the method of equal time interval measurement is more accurate to measure the radon exhalation rate.The design of the measuring parameter optimization system for Radon exhalation rate provides the rapid optimization of measurement parameters and the rapid calculation of radon exhalation rate for the measurement of radon exhalation rate by double chamber equilibrium method,which can improve the efficiency of radon exhalation rate measurement.