Radiation is nothing but particles (like alpha or beta particles) or waves (gamma waves) which have a potential to cause tremendous damage to the human body when exposed to a high dose in a short period of time. This article attempts to explain the ways in which radiation can be measured.
1. Know the units. No measurement is useful if you don't know what the reading actually means. Followed by the magnitude(the number) is a unit.There are many units which are used to measure radiation for different purposes.
2. Use a Geiger Counter. A Geiger counter has a Geiger-Mueller (G-M) Tube which is filled with gas which creates an electrical pulse which is converted to a reading and shown on the meter. It may also have a speaker which turns each interaction into audible clicks.The common readout units are roentgens per hour (R/hr), milliroentgens per hour (mR/hr), rem per hour (rem/hr), millirem per hour (mrem/hr), and counts per minute (cpm)and is usually specified in the manual and is sometimes visible on the display.
3. Use a MicroR meter which has a Sodium Iodide detector. As a crystal of sodium iodide creates a flash of white light when struck by radiation, makes it a useful radiation detector. A sensor converts the flash of light to an electrical signal. This is used as a single channel detector to identify a radioactive substance. MicroR meters also give an audible click when it detects radiation, making it useful to point out the direction of a radioactive substance substance.
4. Use a Neutron REM meter With a Proportional Counter. This device, as the name suggests creates an electrical pulse when a neutron interacts with the apparatus.These counters require a large amount of hydrogenous around them to slow the neutrons down as high speed neutrons will just whiz by without interacting at all.
5. Use an Ion Chamber. An air filled chamber with electrically conductive walls along with a central anode which works at a relatively low voltage. When x-rays or gamma rays interact with the air surrounding the anode, electrons are released which are collected by the anode. The Anode then generates a small current which is measured by the meter and is displayed.The machine gives a reading related to the absorption of radiation by air which needs to be converted to a reading related to absorption by tissue.