Published: Oct 12, 2018
The ionisation chamber is a device designed to measure Ionising Radiation exposure. In simple terms, it consists of a chamber which may either be sealed (containing a gas) or vented to free air. Within the chamber are two electrodes to which a high potential difference (voltage) is applied. If an ionisation event occurs within the chamber it will create an Ion Pair within the fill gas. These ion pairs will migrate to the respective positive and negative electrodes which lead to a reduction in current which, can be detected and measured within external circuitry. Air-filled chambers made of tissue equivalent materials are particularly useful for measuring body radiation exposure (Absorbed Dose). They tend to have a slow response time and are susceptible to changes in climate.