Screening and analysis of ²²²Rn concentration data under the simplified correction model for calculating the radon exhalation rate

The aim of this study is to improve and simplify the measurement of radon exhalation rate using the closed-loop accumulation method. Based on the ²²²Rn concentration data obtained from reference the standard module of uranium ore sands and cement, this work simplifies the ²²²Rn concentration growth model for calculating radon exhalation rate using the least squares method and proves its accuracy. Through fitting residual analysis, anomalies are screened at the significance level of α = 0.05 to enhance fitting precision. Herein, the influence of the starting point on the fitting effect and the calculation of radon exhalation rate is explored. The results indicate that after screening anomalous data, the fitting effects of the two sets of experimental data are further improved, and the relative errors in radon exhalation rate measurements are reduced from 1.77 to 1.41% and 13.08 to less than 10% respectively.