The accurate measurement of 220Rn is important for dosimetry evaluation of natural radiation exposure. In thiswork

based on three commonly used radon measuring devices

i.e. AB5

RAD7 and

AlphaGuard

we developed their use for 220Rn measurement

and their experimental results were compared. The AB5 grab measurement method is simple in principle with stable measurement results

and can be used as a reference method of measuring 220Rn

through its lower detection limit is a little higher. The 220Rn measurement result given by RAD7 is influenced by the status of desiccant and need a timely calibration. AlphaGuard flow mode has the advantage of low detection limit

but can only be a general reference

because of its sampling flow rate and the status of front-end sampling pipe.