The measurement system for radon exhalation rate in open loop is validated. It shows that the radon exhalation rate from medium surface obtained is very good to match the reference value. The time expression when the radon concentration in the chamber tends to a constant value is obtained by theoretical analysis. A method is proposed that a chamber with bigger bottom acreage is used and a adjust valve is added to lower the flux of pump, such increasing the radon concentration in the chamber and reduci...
