Caspar Menkman

An interview with the Geiger Counter.

Dev Camp Day 1

This second installment of interviews with sensors features Sparkfuns home build Geiger-counter. This self-proclaimed king of sensors measures the amount of gamma-,beta and alpha radiation present in any object .


Geiger-Counter -

Can you tell me in short what radiation is?
I can. Radiation is the movement of electromagnetically charged particles that move through a vacuum or medium.

Sounds harmless enough.
It's not. I am really special. I pick up Ionizing radiation that consists of subatomic particles energetic enough to detach electrons from atoms or molecules. When these come in contact with living tissue it can kill.

Ok, how do you that?
When you pass me over any material that has ionizing electromagnetic particles they will pass through a window that only lets them through and keep all other elements out. Behind this window is my Geiger-tube filled with a mixture of argon and methane, both substances that are easily ionized.

Yes, like I said. The process of detaching electrons from atoms and/or molecules. After this separation the molecule or atom will form new bonds, but these can be different then the ones before. This could lead to mutation.

What happens with the ionized electron?
It combines with a positive electrode creating a pulse. Which is easily measurable nowadays.

Ok sounds complicated.
Yes and I use around 250 voltt! That is about 50x the power that is used by other sensors. Making me the king of sensors.

Some might say that is a bad thing.
I don't believe in bad things

Is there any use for you outside of Chernobyl?
Well firstly radiation is ubiquitous. At this moment gamma, beta and even alpha rays could be passing through your head. These rays can be measured and used to create random numbers. And those can be used for things like computer encryption.

Wow you really are the king of sensors...
Too true! and remember kids you can't keep me in your pants (as I radiate a little bit myself).