[en] A new radon transfer line was constructed from a design modified from the earlier one of Lucas. A roller-type peristaltic transfer pump and a pressure-sensitive transducer were substituted for the previously used equipment. The electrical and electronic equipment and operating switches are consolidated in a single control panel. Black or amber pure gum, latex dipped tubing were shown to have a minimum memory effect for radon, and a silicone tubing also appears to be suitable. The precision of measurement was about 2.7% (S.D.), based on eight replicate measurements with a single standard solution of radium. During the course of these tests, it was found that part of the variability was due to leakage of radon from the flask that contained the radium