How the sensor sees: optical COâ‚‚ vs MOX
COâ‚‚ is read by pulsing infrared light the gas absorbs and listening for the pressure wave. VOCs are read by watching a hot ceramic surface change conductance. Different physics, different limits.
Articles tagged "How the sensor works"
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Cross-sensitivities: what confuses each sensor
Every sensor has things it sees that it shouldn't. Knowing the cross-sensitivities is how the dashboard tells you the right story.
Why your reading differs from the nearest EPA monitor
Three reasons your number rarely matches the official outdoor AQI: hyperlocal variation, time resolution, and calibration class.
How air-quality sensors work
The Terrestream stack combines direct measurements, index outputs, context sensors, and interpretation. Those are different evidence classes, and the distinction matters.
PM sensor accuracy and aerosols
Optical PM sensors estimate mass from scattered light. They are powerful for building telemetry, but aerosol chemistry and particle shape still matter.
VOC Index vs TVOC
VOC Index is a relative signal from a MOX gas sensor. TVOC is a concentration-style lab concept. They should not be collapsed into the same claim.
NOx Index vs NOâ‚‚
NOx Index is a combustion-pattern signal. It is not a regulatory NOâ‚‚ concentration measurement.
Breathe Better. Live Smarter.
Turn air-quality knowledge into action.
One sensor. Twelve signals. Indoor readings connected to outdoor context and plain-English recommendations. Everything you just read can be measured live in your own home.
$249 USD one-time
Buy Terrestream Explore the sensor- No subscription required
- 30-day returns
- 1-year limited warranty
- Fast shipping via FedEx
Six sensors. Twelve signals.
Built on genuine Sensirion, Bosch, and Texas Instruments sensors.
- COâ‚‚
- IAQ
- VOC
- NOâ‚“
- PM1
- PM2.5
- PM4
- PM10
- Temperature
- Humidity
- Pressure
- Light
Included
- In the box: the sensor, USB-C cable, power adapter, and printed field guide
- Dashboard and mobile app included
- Privacy-first air data
Works with
- Home Assistant
- MQTT
Home Assistant
MQTT