Owing to the inherent limitation of the internal pulse ionization chamber within the AlphaGUARD PQ2000 radon monitor, that is, its inability to discriminate the energy levels of \(\alpha\) particles, the ingress of \(^{220}\) Rn from the surrounding environment, along with its decay progeny, poses a substantive challenge in accurately determining the \(^{222}\) Rn concentration in the measurement outcomes. Among these, the protracted influence primarily stems from the two enduring decay progenies, namely \(^{212}\) Pb with a half-life of 10.64 h and \(^{212}\) Bi with a half-life of 60.54 min. This study explored the influence of \(^{220}\) Rn progeny on the measurement results of an AlphaGUARD PQ2000 radon monitor by developing a theoretical calculation model. The response coefficient related to the residual \(^{220}\) Rn progeny within the AlphaGUARD PQ2000 radon monitor was experimentally validated. In addition, this study investigated the effects of temperature and wind speed on the sensitivity of the instrument to \(^{220}\) Rn gas. The research findings revealed commendable agreement between the experimentally measured response coefficients of the residual \(^{220}\) Rn progeny and the corresponding values derived from the theoretical model. Notably, both the response coefficients of the AlphaGUARD PQ2000 radon monitor to \(^{220}\) Rn gas and its internal residual \(^{220}\) Rn progeny increased with elevated temperatures and increased wind speeds, providing a reference for correcting the impact of \(^{220}\) Rn and its progeny on the measurement results of \(^{222}\) Rn concentration obtained using the AlphaGUARD PQ2000 radon monitor.
