Radon Level Monitoring Dashboard

The default band is below 100 Bq/m³ (WHO reference; many national action levels are 100–200 Bq/m³ / 4 pCi/L). Treat it as a sensible starting point — your own specification, regulator, equipment manual or product datasheet sets the authoritative limits, and you can read your true band straight off the worst case those documents allow. Edit the readings against whatever band applies to you.

The long-term average, not the daily spikes. Radon entry varies strongly with weather (low barometric pressure draws more soil gas in), soil moisture, and ventilation — and it's typically highest in winter when buildings are sealed and heated (the 'stack effect' pulls soil gas up). A single short reading can mislead in either direction. Health authorities base action levels on long-term (months-long) averages, so a continuous monitor's running mean against the action level (100 Bq/m³ WHO reference, or your national level) is what should trigger mitigation — usually a sub-slab depressurisation system, which is highly effective. Re-test after any mitigation to confirm.

Match the interval to the consequence and the rate of change: where an excursion spoils product or risks safety, log continuously (or as often as you can sample); where it is merely informative, daily or per-shift spot checks suffice. The in-range % and excursion count only mean something if your sampling is regular — sparse, irregular readings hide the excursions between them.

Yes — every reading is stored in this browser's localStorage on your device and nothing is uploaded to any server, which also makes the dashboard usable on sites with strict data policies. For shared, audit-grade records across a team or for regulatory retention, export the values into your own system.