Radiation detectors are devices used to detect and measure ionizing radiation. These devices, known as radiation dosimeters, are specifically designed to measure the amount of energy deposited by radiation in matter and living tissue. There are several methods and equipment used to detect radiation, such as film badges, gas ionization devices, Geiger-Muller counters, radon detectors, personal radiation detectors, fog chambers, and scintillation counters. As the voltage in the ionization chamber increases beyond V-2, the current increases due to electrons moving through the upper electric field and gaining enough energy to cause secondary ionization.
This results in a larger pulse being obtained. Alpha particles are found in the region of the voltage plateau, which produces a large amount of primary ions. The amplitude of the pulse is proportional to the energy of the original ionizing particles, making it useful for detecting and identifying the nature of the radiation. These range from large fog chambers to personal portable devices, such as a counter used to detect radiation.
Photographic film plates can also be used to detect radiation, as ionizing particles interact with the film to change its optical density. In addition to ionization of gases, other methods can be used to detect radiation, particularly in laboratory environments. For quantitative work, radiation measurement is performed with a scintillation counter, an instrument that counts the intensity of radiation. These detectors indicate high levels of radiation for some time, while other detectors indicate levels of radiation at that point.