- I just finished with the tests on my WW11 Bendix, pioneer oxygen guage. the dial was 37,608 c/m, the radon in charcoal was 749 c/m to 767c/m second reading. and the radon reading from the radon detector after 48 hours was 193.9 pCi/L. The measurements were taken with a Eberline portable scaler, and my radon detector. Safety Pro.