A geiger counter that’s simple enough for children to use has been developed for the Japanese market following a spike in demand for such products as a result of the Fukushima reactor meltdown. ‘Peramos‘ (short for “personal radiation monitoring system”) has simple controls and display so anyone can operate and understand it.
There are LED lights on the geiger counter that change colour to indicate if there is an increase in radiation levels. They are green for normal, yellow for attention, orange for warning, and red for danger.
via PSFK
