Geiger counter

имя существительное [физика] счётчик Гейгера

Большой англо-русский словарь

Geiger counter

noun Etymology: Hans Geiger died 1945 German physicist an instrument for detecting the presence and intensity of radiations (as cosmic rays or particles from a radioactive substance) by means of their ionizing effect on an enclosed gas which results in a pulse that is amplified and fed to a device giving a visible or audible indication

Merriam-Webster's Collegiate Dictionary