Radon exhalation rate from soil is a critical factor in evaluating environmental radon levels. However, AlphaGUARD PQ2000PRO may have some sensitivity towards thoron, which can have a significant impact on radon measurement. The traditional radon exhalation models generally ignore the presence of thoron, leading to an overestimation of the radon exhalation rate from soil. To handle this issue, a new model was proposed based on an analysis of several previous studies on radon exhalation theories. To prove the feasibility of the model, the radon exhalation rate measurements were performed by two...