A device generically called a Radiac, however there are dozens of different kinds of Radiacs which operate by different principles and measure different things. Some are:
A Geiger counter
Geiger counter
a neurometer
A Geiger-Muller counter
Geiger counter
Geiger muller counter
Geiger counter .
A Geiger counter.
Geiger Muller tube with ratemeter.
It's called a Geiger counter.
The Geiger counter.
An instrument for detecting and measuring electricity especially as an ionization of the ionization of air by radioactivity.
The smallest change in a measured physical quantity that an instrument is capable of detecting.
Geiger Counter *********Contributed by Czar Acumen**********************
The cloud chamber, or Wilson chamber.
The electroscope is an instrument for detecting an electric charge by measuring mechanical forces between two charged bodies.
An instrument for detecting and measuring electricity especially as an ionization of the ionization of air by radioactivity.
Geiger Counter. Or Gieger Counter...not certain of spelling.
Radar.
It is Radiograph and it is used by a Radiologist.
The smallest change in a measured physical quantity that an instrument is capable of detecting.
A Geiger Counter
It's a useful instrument for detecting weather. It measures air pressure.
Geiger Counter *********Contributed by Czar Acumen**********************
The cloud chamber, or Wilson chamber.
An electroscope is an instrument for detecting the presence of static electricity.
A galvanometer is a type of ammeter: An instrument for detecting and measuring electric current.
a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake)