CO₂ sensing
True NDIR CO₂ sensing
Infrared sensing built specifically for measuring CO₂.
400–5,000 ppm ±(50 ppm + 5%) NDIR infrared
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Atmosense Core CO₂ Wi-Fi Air Quality Monitor
Selected setup: 1x Core CO₂
£49.99
Free UK Delivery (3-6 days, Monday to Friday, excluding bank holidays)
30-Day Returns (Easy Self-Service returns)
2-Year Warranty more info.
Good to know before you buy
Not a CO alarm: Core CO₂ measures carbon dioxide (CO₂), not carbon monoxide (CO). It can not replace a certified carbon monoxide alarm.
Power adapter: Includes a high-speed USB-C charging cable compatible with any standard 5V/2A UK mains plug.
This device is designed for indoor use only.
Intelligent indoor air monitoring
Know when to ventilate.
Sealed homes trap humidity and carbon dioxide (CO₂), creating the ideal conditions for condensation and damp. Atmosense Core CO₂ accurately tracks 3 climate factors in real time—giving you the data you need to ventilate efficiently and protect your living space.
1 Device. 3 Essential Measurements
A Clearer Picture.
Core CO₂ brings important indoor air and climate measurements together in one place, so you can see what is happening rather than simply guessing.
iOS & Android app
Keep track with the app.
Check your live readings in the Tuya Smart/Smart Life app. You can also review historical graphs and configure phone alerts for the thresholds you choose.
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Live monitoring
Track real-time CO₂, temperature, and humidity trends anytime, anywhere. -
Instant phone alerts
Receive push notifications whenever CO₂, temperature, or humidity reaches your configured alert thresholds. -
Spot trends over time
Explore historical data graphs in the app to identify patterns and changes in your indoor environment. -
Know when to act
Ventilate when CO₂ rises, or act early when humidity points to condensation and damp.
Voice assistants
Works with Amazon Alexa and Google Home.
Works with Amazon Alexa and Google Home through the Smart Life app, so you can ask for the room's temperature and humidity by voice. CO₂ readings are shown on the monitor and in the app.
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"Alexa, what's the temperature in the bedroom?"
Check how warm a room is without picking up your phone. -
"Hey Google, what's the humidity in the living room?"
Keep an eye on moisture while you get on with your day.
Simple to set up. Easy to use.
Set up Core CO₂, connect the app, and start making sense of your indoor environment.
01 · Place
Position Atmosense in the room you want to monitor.
02 · Connect
Connect the monitor to your supported Wi-Fi network and app.
03 · Understand
Use your readings to understand ventilation, comfort, and moisture conditions in your home.
Accurate CO₂ monitoring
See the environment you use.
Atmosense Core CO₂ combines accurate CO₂ monitoring with a clear display and connected insights, helping you take a more proactive approach to indoor air quality.
Power saving
Wake it with a wave.
The screen sleeps after 30 seconds to save power. Wave your hand near it to wake it.
Instant feedback
See it. Hear it. Act on it.
A colour indicator shows your CO₂ level at a glance, and an audible alarm sounds at 1,500 ppm by default. You can silence it on the device or in the app.
Adaptive display
Bright when you need it. Softer at night.
Brightness adjusts to the room, so it is easy to read by day and softer at night.
Product specifications
Product features
Sensors
Carbon dioxide (CO₂) using an NDIR infrared sensor, temperature, humidity, ambient light, and proximity.
Display
Full-colour LED display.
CO₂ alert
Audible alert when CO₂ reaches 1500 ppm (default). The alert level and alert sound are set in the app.
Battery & charging
Built-in 1200 mAh lithium battery, charged by USB Type-C. Charge for 5 minutes before first use.
Up to 13 hours of portable use on a full charge. A full charge takes about 2–3 hours. *For continuous monitoring, keep connected to USB-C power.
Placement
Place on a flat, dry surface out of direct sunlight. Do not block the air inlet or the light sensor on the front. Keep it away from your face, as your breath will raise the CO₂ reading. Perfume, alcohol, cleaning products, cooking fumes, and similar everyday sources can affect readings. Not waterproof.
CO₂ specifications
CO₂
NDIR (non-dispersive infrared) sensor.
Measurement range: 400–5000 ppm
Accuracy: ±(50 ppm + 5% of reading)
Resolution: 1 ppm
Temperature & humidity
Temperature
Measurement range: 0–50 °C
Accuracy: ±1 °C
Display in °C or °F
Humidity
Measurement range: 0–99 %RH
Accuracy: ±5 %RH
Additional specifications
Operating conditions
Temperature: 0 to 50 °C. Keep in a dry environment.
Product specifications
Weight: 98 g
Dimensions: 70 × 84 × 35 mm
Power: USB Type-C, 5 V ⎓ 2 A
Battery: 1200 mAh lithium
Material: ABS
Placement: Desktop / table stand
Certifications
UKCA, CE, RoHS
Package contents
Atmosense Core CO₂ monitor
USB Type-C charging cable
Instruction manual
CO₂ levels
Colour bar
| Good | 400–799 ppm | Green indicator flashes |
| Moderate | 800–1199 ppm | Yellow indicator flashes |
| Poor | 1200–1599 ppm | Orange indicator flashes |
| Unhealthy | 1600–1999 ppm | Red indicator flashes |
| Very Unhealthy | Above 2000 ppm | All four indicators flash |
Alert
An audible alert sounds at 1500 ppm by default, within the Poor band. You can change the alert level or switch the sound off in the app.
The band names above are the manufacturer's labels for the monitor's colour bar. They are not health or safety thresholds.
The Atmosense Core CO₂ measures carbon dioxide (CO₂) for general indoor air guidance. It is not a carbon monoxide (CO) detector or a safety alarm. Readings are indicative and have the tolerances stated above.
App & connectivity
Smart Life / Tuya Smart app
Smart Life or Tuya Smart app for iOS and Android.
Connectivity
2.4 GHz Wi-Fi. Not compatible with 5 GHz Wi-Fi.
Warranty
2-Year Warranty
Every Atmosense Core CO₂ is covered by the Atmosense 2-Year Warranty. Full details here
Note: Features automatic CO₂ baseline calibration and auto-standby power saving (wakes via proximity sensor). For 24/7 continuous monitoring, keep connected to USB-C power.
Frequently asked questions
How accurate is it?
CO₂ accuracy is ±(50 ppm + 5% of reading), so at a reading of 1,000 ppm, the result is within about ±100 ppm. Temperature is accurate to ±1°C and humidity to ±5% RH. Core CO₂ is designed to help you understand how your home's conditions change, not to replace laboratory equipment.
Can I switch between °C and °F?
Yes. You can change the temperature unit between Celsius and Fahrenheit in the app settings or on the device.
Does it need calibrating?
Core CO₂ calibrates itself automatically. After 24 hours powered on, it uses the lowest CO₂ level from the past 24 hours as its fresh-air baseline, so make sure the room is ventilated at some point each day. You can also calibrate it manually: place the monitor in fresh air (about 400 ppm, outdoors or by an open window) for 5–10 minutes, then press the button 3 times quickly.
When will it alert me?
The display shows a colour indicator for your current CO₂ level, and the built-in audible alarm sounds when CO₂ reaches or exceeds 1,500 ppm by default. In the app, you can set your own alert threshold for push notifications. As a rough guide, fresh outdoor air is around 400–450 ppm, and readings that stay above about 1,000 ppm usually mean a room would benefit from more fresh air.
Can I get alerts for temperature and humidity too?
Yes. In the Tuya Smart / Smart Life app, you can set your own push notification thresholds for CO₂, temperature, and relative humidity separately.
Do I need the app?
Core CO₂ shows live readings on its own display. To see readings away from home, view history graphs, and receive phone alerts, connect it to the free Tuya Smart or Smart Life app. An app account is required.
Can I see past readings?
Yes. The Tuya Smart / Smart Life app keeps your readings in the cloud and shows them as daily, weekly, and monthly charts.
Which Wi-Fi does it need?
Core CO₂ connects to 2.4GHz Wi-Fi only, so it won't connect to a 5GHz-only network. Most home routers offer 2.4GHz as well as 5GHz. If setup doesn't work, check that your phone is on your 2.4GHz network while you connect the monitor.
How long does the battery last?
Up to 13 hours of portable use on a full charge, and a full charge takes about 2 to 3 hours over USB-C. For 24/7 monitoring, we recommend keeping it plugged into a 5V/2A power source. To save power when it's running on battery, the screen goes to sleep after 30 seconds and wakes when you wave your hand near it.
Is a mains plug included?
No. The box includes a USB-C cable but not a mains plug. Use a USB mains plug rated 5V/2A.
Where should I put it?
Choose an open spot at around desk or bedside height, away from windows, vents, radiators, and direct sunlight. Avoid placing it right next to where you breathe, as this can briefly spike the CO₂ reading.
What if it isn't right for me?
Core CO₂ comes with a 30-day returns policy and a 2-year warranty. See our returns and refunds page for how it works.