[BetterGeiger]

Beta particles are basically energetic electrons flying around, yes, but for a Geiger counter to detect them they have to be quite energetic in order to penetrate the Geiger tube itself (detection occurs essentially inside the tube, in the gas)... So I doubt that static field is generating electrons anywhere near that energy needed to be detected by a Geiger tube.

[kloch]

Dryer static charges are probably a few keV at most so yeah that shouldn't make it through a metal envelope.

However, I wonder how well shielded the electronics are. In a poor quality design even the static charge fields themselves might trigger a false hit.