What must radiation do in order to be measured by detection equipment?

Detection of radiation relies fundamentally on the interaction between the radiation and the detection equipment. For a radiation detector to measure radiation, it must first interact with the materials or sensing elements within the detector. This interaction produces measurable signals, such as ionization electrons, scintillation light, or other forms of energy that the equipment can process to provide readings about the presence and intensity of radiation.

While radiation may indeed be emitted from a radioactive source and can travel through air, these factors alone do not guarantee detection. The critical aspect is that the radiation interacts with the detector's sensitive area, which allows the detector to register and quantify the radiation. Similarly, the notion of ionization pertains to a specific outcome of such interactions but is not a requirement for measurement across all types of radiation detection methods. Different detectors may respond to radiation in various ways, all of which depend on this essential interaction.