A wireless-enabled sensor system for distributed radiation detection on Android cellphones

This paper reports a wireless-enabled sensor system for detecting the strength and distribution of radiation in a target area using multiple distributed sensor modules. An Android smartphone is used for the user interface. Each sensing module consists of a microdischarge-based miniaturized radiation detector and its interface circuit, a microcontroller unit and a Bluetooth interface for wireless communications with the phone client. Other types of radiation detectors can also be potentially used. The phone client automatically scans and interrogates the sensor modules in range (up to 100 m possible), and acquires and interprets the radiation data and location coordinates from each module. The prototype of the sensor module has an overall size of 50 × 50 × 35 mm³, and is powered by two 3.6 V CR123A rechargeable lithium ion batteries. The power consumption of each sensor module is 225 mW in active sensing mode which is typically <;20 s per acquisition cycle, and 7 mW in sleeping mode.