How to Operate a Geiger Counter

Activate the power switch on the Geiger counter. It should have either a switch or a power button. It is battery-powered, so the batteries should be fresh for the most accurate reading.

Run the Geiger counter over the substance being tested. If you are testing the air, walk around the area to allow the air to filter through the Geiger counter.

Examine the readout of the device and listen for clicking. An increase in clicking means there is a higher level of radiation detected, and if the meter starts going to the right or spiking, there is a high level of radioactive material detected. The number of clicks or the reading on the meter can be used to determine the radioactivity of the material being tested.