Patent ID: 8712700

Claim:
A method of detecting a fraction of remote origin of 222 Rn present in a measuring site (Z) for monitoring dynamic phenomena inside land crust, comprising the following steps: a) analyzing the measuring site (Z) in order to determine a typical ratio between 222 Rn of local origin and 220 Rn of local origin, said typical ratio being proportional to a ratio between an emission coefficient ε 222 Rn of said 222 Rn of local origin and an emission coefficient ε 220 Rn of said 220 Rn of local origin, said ε 222 Rn and ε 220 Rn being measured on ground samples collected from the measuring site (Z); b) measuring, at predetermined time intervals, alpha spectroscopy in the measuring site (Z) using a measuring chamber ( 2 ); c) elaborating said alpha spectroscopy in order to find total concentration of said 222 Rn and total concentration of said 220 Rn present in the measuring site (Z); d) determining concentration of said 222 Rn of local origin by multiplying said total concentration of said 220 Rn with said typical ratio; and e) subtracting said concentration of said 222 Rn of local origin from said total concentration of said 222 Rn to obtain a concentration of said fraction of remote origin of said 222 Rn.