Posted on 24th Oct 2017
In my original post of Smartphones as Dosimeters I mentioned that I would follow it up with a post about how smartphones detect radiation. It is actually quite simple.
Imagine the moment you take a photograph using your smartphone. The camera sensor detects light photons which is register and turned into a picture. This is exactly the way a smartphone registers both gamma and x-ray radiation. The problem is that there is an overload of light when you take a picture, the X-ray are simply overwhelmed and don’t show up. So, let’s tape off the camera lens and take a picture.
A lot of people imagine the picture to show up an almost perfect black.
Except it doesn’t…there will always be a certain amount of noise in any picture you take. Normally you don’t notice this as the light photons are so prominently present.
This noise is caused by a multitude of sources, one of which is ionising radiation. So, when we take a (taped off) picture is a ‘high’-dose environment we get noise, the more noise the more radiation. As mentioned before there are several apps available which correlate the noise to a certain radiation dose.