What's a Geiger Counter?

A Geiger counter is an instrument used for detecting and measuring ionizing radiation. Also known as a Geiger–Müller counter, it is widely used in applications such as radiation dosimetry, radiological protection, experimental physics, and the nuclear industry.

What does a Geiger counter do?

Geiger counters are commonly used to measure the amount of radioactivity, but there are other types of detectors that may be used.

What do Geiger counter readings mean?

The level of radiation is expressed as an amount of radiation (in a unit called Sieverts) per hour of exposure. So if the Geiger counter reads 0.22 microSieverts per hour (as it does in the photo above), that means I received . 22 microSieverts of radiation while having my hour-long breakfast in Kiev.