If only I'd had the foresight to indicate that cosmic & radon removal weren't something to fuss about on handheld consumer click counters <doh> - thank you for chipping that in.

Might be worth pointing out the principle reason preventing radon removal from a click counter, no matter how sensitive, is the lack of a channeled spectrum bucketing counts by energy level, and the main reason cosmic cannot be removed is the lack of channeled stacked height descent readings allowing a ground level current cosmic estimate.

> When capturing open-air terrestrial tracks they are more or less uranium and thorium detectors.

and Potassium also- just all bundled together as a total count with no discernment.

Still, perhaps one day in the future, just as modern GPS carry a coarse ground / ellipsoid separation model in order to return 0 elevation at the seashore, perhaps rad counters will carry a coarse global radiation background model to focus on counts over and above the expected.

( again, unlikely due to lack of real sensitivity and channel bucketing )