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Air quality · Source-based buying advice

Radon and CO2 monitors answer different questions

Choose the sensor for your question: radon, CO2 or carbon-monoxide protection. Compare the measurements in Home 2, View Plus and RD200.

By EcoGeosEditorial review: October 12, 2026Documentation-based review

Radon and CO₂ use dedicated measurement systems. For both readings, choose a model that includes both sensors.

Choose the readings you want

Radon is a radioactive gas; the EPA Citizen's Guide explains why testing is needed to establish a home's radon levels. CO₂ monitoring measures a different gas.

EPA's indoor-monitor guidance includes rising classroom CO₂ as a possible prompt to consider ventilation, while emphasizing that monitors only detect what their sensors are designed for. Treat a CO₂ record as information about that measured parameter and its context. Use a dedicated radon sensor for the radon record.

What the three shortlisted models measure

Model Radon CO₂ Other documented measurements
Corentium Home 2 Yes No Temperature, relative humidity
View Plus Yes Yes PM2.5, VOCs, temperature, relative humidity, pressure
RadonEye RD200 Yes No Dedicated radon measurement

Sources: Home 2 manual, View Plus specifications, RadonEye specifications. Model names matter: check the sensor list for the exact model.

The View sensor specifications describe an infrared CO₂ sensor and alpha-spectrometry radon detection. These are separate measurement systems inside the same device. Read the two records separately.

CO₂ is also different from carbon monoxide

CO₂ means carbon dioxide; CO means carbon monoxide. The CDC's CO guidance describes carbon monoxide as an odorless, colorless gas that can cause sudden illness and death, and recommends household CO detectors. Household CO protection uses dedicated CO alarms.

Use dedicated smoke and carbon-monoxide alarms for immediate warning, alongside the environmental measurements described in the View Plus starter guide.

Find the model for your question

If you only need radon monitoring, compare screen, history and connectivity in the radon buying guide. If you want both radon and CO₂, compare View Plus and whether you will use its additional measurements.

Before ordering, find the exact sensor list and units in the manufacturer's documentation. Read each value according to the pollutant it measures. The sensor guide explains how to check those limits.

Documentation used

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