Final answer:
Intrusion detectors are categorized into three classes: Geiger counters, scintillators, and dosimeters. These devices are used to measure different aspects and types of radiation, ensuring safety in environments with potential exposure to ionizing radiation.
Step-by-step explanation:
Intrusion detectors, which are crucial for ensuring the safety and security of spaces and information, can be categorized into three main classes. These categories include: (a) Geiger counters, (b) scintillators, and (c) dosimeters. Each of these devices plays a pivotal role in measuring radiation but operates on different principles to detect ionizing radiation.
A Geiger counter, through the use of a Geiger-Müller tube, can detect and measure the intensity of ionizing radiation. Scintillators are devices that absorb high-energy photons and reemit the energy as visible light, which is then detected and measured. Dosimeters, on the other hand, are used for measuring an individual's exposure to radiation over a period of time, often used by workers in fields where radiation exposure is possible.