Camera-based ionizing radiation analysis
Cover your camera lens completely with any opaque material — black electrical tape, multiple layers of thick cloth, or black foam — to block all visible light. Ionizing radiation (gamma, X-ray, beta) then strikes the CMOS sensor directly, creating bright spots in an otherwise dark image.
The app subtracts a background image from a detection image, filters by threshold, and counts pixel clusters as radiation events.
Real-time: Start camera → Capture background → Set exposure & threshold → Start detection
Static: Upload background image → Upload detection image → Adjust threshold → Results auto-update
Calibrate: Enter known source details → Get dose rate conversion factor
This tool is significantly less sensitive than dedicated radiation monitoring equipment. Professional Geiger counters and dosimeters are purpose-built with calibrated detectors optimised for radiation detection. This app uses a standard smartphone camera sensor — a much thinner silicon layer — meaning it will only respond to moderate-to-high radiation fields and may miss low-level exposure entirely.
Use this for educational demonstrations, qualitative checks, and research experiments — not as a substitute for certified dosimetry instruments.
Pixel-wise: Subtracts each pixel individually — best for sensors with fixed hot pixels or spatial noise patterns.
Mean: Subtracts the global mean difference — faster, best for uniform sensors.
Hybrid: Uses the larger of the two — balanced performance, recommended for most cases.
Step 1 — Prepare your source. You need a radioactive source with a known activity (in MBq), such as a radiopharmacy calibration source or a certified check source. Note its activity at the reference time.
Step 2 — Cover the camera. Apply opaque material over the lens as usual, then position the camera at a measured distance from the source centre. Record this distance in metres.
Step 3 — Run a detection. Go to the Real-time or Static tab and perform a measurement. Note the Net Events count and the exact exposure time you used.
Step 4 — Enter values below. Select the correct isotope, fill in the activity, distance, net events, and exposure time, then click Calculate Calibration Factor. The factor is automatically saved and applied to all dose rate readings.
Step 5 — Verify. Re-measure the same source — the displayed dose rate should reasonably match the theoretical value shown after calibration. Expect ±20–50% uncertainty due to sensor geometry and energy dependence.
Theoretical dose rate: Ḣ = (Γ × A) / r²
Normalized count rate: C = Net Events ÷ Exposure Time
Calibration factor: k = Ḣ / C (µSv/hr per event/s)
Once saved, dose rate = k × events/s in all detection modes.