EDN’s teardown of X-Sense’s new XR0A-iR smart radon alarm shows that the core sensing element is a large-area PIN photodiode used for continuous alpha spectrometry. The device is intended to collect, count, and distinguish alpha-particle energies so it can estimate the cancer risk associated with radon gas in residential air.
According to the article, the detector sits behind a plastic structure that does not appear to block the relevant radiation path. The sensor’s operating principle follows the familiar PIN structure: heavily doped p-type and n-type regions surround an intrinsic layer, which is where the alpha interaction generates carriers. The article notes that the exact impact position is not important here; what matters is that an alpha particle has struck the semiconductor medium at all.
The teardown also found a dense analog section beneath a protective cover, which is suspected to include the circuitry needed to bias the detector at a higher voltage. A reader comment in the article specifically points to a charge-pump topology, such as a Dickson, Greinacher, or Cockcroft-Walton multiplier, to create the electric field required to sweep out carriers before recombination. The same discussion suggests the bias level is probably below 60 V.
For the system side, X-Sense uses an AIartificial intelligence-Thinker Ai-WB2-32S module for 2.4 GHz Wi-Fi and Bluetooth LE, plus a Nations Technologies N32L406MBL7 microcontroller based on a 32-bit Arm Cortex-M4 core. The MCU1. microprocessor control unit2. mobile calibration unit3. microcontrollerA microcontroller is a compact integrated circuit designed to execute embedded control tasks in electronic systems. includes onboard flash and SRAM1. static random access memoryMemory technology or system for temporarily or permanently storing digital information.2. static random-access memorySRAM is used here as a test vehicle for embedded memory performance., which explains the lack of discrete memory devices on the board.
In other words, the XR0A-iR combines a semiconductor radiation detector, analog front-end biasing, and low-power wireless processing in a consumer radon monitor. EDN also notes that the unit uses passive airflow rather than a fan, and that X-Sense positions it as its first connected radon product.