Ionizing radiation can not be directly detected with the human senses. So we have developed many ways to detect it. Some devices work best for specific types of sources and purposes. Many dosimeters are now classified as self-reading and/or alarming devices. These instruments allow the user to select early warning and alarms for the amount of exposure that they receive and also to be warned of significantly higher than expected radiation levels. They also have digital read outs for instant access to the exposure monitoring data. These devices can also be linked electronically to a database or software program to maintain records and configure the devices.
Radiation detector PM1904 for iPhone. A new type of pocket dosimeter. When preset radiation thresholds are exceeded, device provides LED light alarm. All measurements are recorded in non-volatile memory. Courtesy Polimaster Inc.