Kauntala ya Geiger-Miller, kapena Geiger counter mwachidule, ndi chida chowerengera chopangidwa kuti chizindikire kuchuluka kwa ma radiation ya ionizing (tinthu tating'onoting'ono ta alpha, tinthu ta beta, cheza cha gamma, ndi X-ray).Pamene mphamvu yamagetsi yomwe imagwiritsidwa ntchito pa kafukufukuyo ifika pamtundu wina, ma ion ionized ndi cheza mu chubu akhoza kukulitsidwa kuti apange kugunda kwamagetsi kwa kukula komweko ndikujambulidwa ndi chipangizo chamagetsi cholumikizidwa, motero kuyeza kuchuluka kwa cheza nthawi ya unit.