Other ways of detecting radiation
Photographic film
When exposed to ionising radiation, photographic film will turn from being transparent to dark and non-transparent. This effect is used by people who work with radiation in detectors called film badges.
A Chemical sheet capable of detecting light and ionising radiation. is placed inside the film badge holder. The film is already in a paper covering.
On each side of the badge are various 'windows' - numbered 1-6 in the picture above.
The open window allows all types of radiation through, therefore showing exposure to Beta and Gamma radiations.
Windows 2 and 3 are plastic of different thicknesses allowing the person examining the film to tell what kinds of Beta radiation they have been exposed to. Windows 4,5 and 6 are of different metals (including lead and tin) allowing the detection of gamma rays and other ionising radiations.
The final exposure of the film will show how much and what kind of radiation the worker has been exposed to.
Film badges worn by medical personnel dealing with radiation are checked regularly.
Cloud chamber
A Closed chamber with vapour contianed inside capable of showing the paths in air taken by ionising radiation. is a small container full of saturated water vapour (like a cloud).
Inside the chamber, ionising radiations like Alpha and Beta will be indicated by tracks in the vapour.
Large Alpha particles have short broad tracks while Beta particles have longer thinner tracks.
For a better description, check out this video which demonstrates this detector:
A comparison of alpha, beta and gamma
