Real-time environmental radiation monitoring from Lancashire, United Kingdom
The dashboard displays real-time CPM and µSv/h readings with interactive time-range charts, a moving average trend line, period min/max, and a colour-coded dose scale — all auto-refreshing every 30 seconds.
| Card | Description |
|---|---|
| ⚡ Count Rate | Live Counts Per Minute (CPM) from the Geiger tube |
| ☢ Dose Rate | Converted µSv/h using the SBM-20 factor of 0.0057 |
| 🟢 Radiation Level | Status: Normal / Slightly Elevated / Elevated / High / Danger |
| 📊 Data Points | Number of readings in the selected time window |
| 📈 Period Average | Mean µSv/h for the active range (1hr / 24hr / 7 Day / 30 Day) |
| ↕ Period Range | Low ▼ and High ▲ µSv/h — High coloured to match the dose scale |
Charts show raw readings plus a smoothed moving average trend line. The µSv/h chart includes a green threshold line at 0.30 µSv/h marking the normal background ceiling.
| Level | Range | Significance |
|---|---|---|
| 🟢 Normal | < 0.30 µSv/h | Natural background. Global average 0.08–0.30 µSv/h |
| 🟡 Slightly Elevated | 0.30 – 1.0 µSv/h | Above typical background; not concerning for short exposure |
| 🟠 Elevated | 1.0 – 5.0 µSv/h | Warrants investigation of source |
| 🔴 High | 5.0 – 20.0 µSv/h | Significantly above background; may require reporting if persistent |
| ⛔ Danger | > 20.0 µSv/h | Restricted zone level; significant health risk with prolonged exposure |
| Dose / Limit | Value |
|---|---|
| Annual public limit | 1 mSv/year ≈ 0.11 µSv/h continuous |
| Nuclear industry worker limit | 20 mSv/year |
| Chest X-ray | ~20–100 µSv total |
| CT scan | ~10,000–20,000 µSv total |
| Acute radiation sickness threshold | ~500,000 µSv received in a short period |
Typical reading: 0.05–0.20 µSv/h is normal. Readings consistently above 1.0 µSv/h without a known source (e.g. a mineral sample) are worth investigating.
MCU : ESP32-C3 Super Mini
Tube : SBM-20 Geiger-Müller Tube
Factor: 0.0057 µSv/h per CPM
IoT : ioT Server (field1 = CPM, field2 = µSv/h)
Power : USB-C
The ESP32-C3 reads pulses from the SBM-20 tube, calculates CPM and µSv/h, then pushes readings to the IoT server every 30 seconds over Wi-Fi.
Natural background radiation (global average) ≈ 0.10–0.30 µSv/h
☢ Geigerduino · ESP32-C3 + SBM-20 · Lancashire, UK · 2025