A	Area of the air inlet(s) of the detector (RADUETs or AlphaGUARD)
C bg	Concentration indicated by AlphaGUARD before starting exposure to thoron
C ex	Concentration indicated by AlphaGUARD during exposure to thoron
C Tn, in	Thoron concentration in diffusion chamber of the detector (RADUETs or AlphaGUARD)
C Tn, out	Thoron concentration in a thoron calibration chamber
d	Thickness of a porous medium (filter or sponge)
D p	Diffusion coefficient in a porous medium (filter or sponge)
N bg	Background track density on CR-39
N ex	Track density on CR-39 formed after exposure of RADUETs to thoron is completed
R A	Responses to thoron for AlphaGUARD
R R	Responses to thoron for RADUETs
t	Time
T	Time for exposure of RADUETs to thoron
u	Air velocity induced by pressure gradient in a porous medium
V	Volume of the detector (RADUETs or AlphaGUARD)
γ	Air exchange rate of the detector (RADUETs or AlphaGUARD)
λ	Decay constant of thoron