Last updated: 19 July 2026 · Originally published April 2026 · By James Wright
Last checked: 19 July 2026. Research-led guide; Smart Home UK has not performed the previously claimed physical monitor tests.
Measure the pollutant you care about
| Reading | What to verify | Common limitation |
|---|---|---|
| PM2.5/PM10 | Particle sensor, update rate and cleaning guidance | Humidity and placement can affect readings |
| CO₂ | Exact sensor technology and calibration method | Estimated eCO₂ is not the same as direct CO₂ measurement |
| VOC | Whether the output is an index or concentration | Broad response does not identify a chemical |
| Radon | Dedicated radon sensor and required averaging period | Short readings are not a long-term assessment |
| Carbon monoxide | Use a certified life-safety CO alarm where required | A general air monitor is not automatically an alarm |
Buying checklist
Confirm the exact sensors, calibration, local display, history/export, account/cloud dependency, privacy, power, placement, warranty and UK availability. Do not infer sensor accuracy from app quality or one owner review.
For health concerns or hazardous readings, follow current NHS, UKHSA, local-authority or emergency guidance rather than a product ranking.
Smart Home UK Team - Research-led UK smart-home editors who compare manufacturer specifications, UK availability, verified owner feedback and authoritative sources. Independent. No sponsored placements.