The RTCA 4 Pass Charcoal Canister is part of the radon test kit
test program at Consumer Reports. In our lab tests, radon test kit
models like the 4 Pass Charcoal Canister are rated on multiple criteria, such as those listed below.
Accuracy measures how closely results matched those from the calibrated radon monitor we used as a benchmark. Those rated poor were off by almost 40 percent; ones rated fair, by less than 25 percent.
Reliability indicates how similar the readings were for several samples exposed under identical conditions. Those rated fair varied by more than 10 percent and up to 15 percent; those rated very good, by less than 8 percent.