How does a Geiger counter detect radiation, and why does it make that clicking noise?
In: 4333
Certain kinds of radiation can knock the electrons off atoms, turning them into ions (charged particles). This can turn a gas that can’t conduct electricity into ions that can.
Geiger counters exploit this…they setup a tube of low pressure gas with a really high electrical voltage across the gas. The gas is normally an insulator (doesn’t conduct electricity), but if radiation comes through it ionizes the gas so that it becomes conductive and electricity can flow. That creates a big electric pulse that’s easy for the electronics in the counter to measure.
It’s also really simple to connect that pulse signal to a speaker. And the sound of a short electrical pulse through a speaker is…a click.
So the clicks are literally the electrical pulses released by each radiation particle zipping through the counter. It’s a simple, visceral, and effective way to tell the operator what’s going on.
Latest Answers