Aranet
Aranet Aranet4 Pro
$250
Aranet Aranet4 Pro Overview
The Aranet Aranet4 Pro is a premium CO2 monitor that tracks CO2, Temperature, Humidity and Atmospheric Pressure. It uses a NDIR sensor — the technology we recommend for reliable CO2 readings — with a stated accuracy of ±30 ppm across a 0-9999 ppm measurement range. At $250, it is aimed at professional applications, on-the-go monitoring, classrooms and offices.
In day-to-day use, the Aranet4 Pro offers an onboard display, so you can read levels at a glance without opening an app, plus Bluetooth connectivity for logging trends and setting alerts, plus a portable design with 2+ years of battery life, making it practical to carry between rooms or when travelling.
Best For
Full Specifications
| Price | $250 |
| Sensors | CO2, Temperature, Humidity, Atmospheric Pressure |
| Sensor Type | NDIR |
| Connectivity | Bluetooth |
| Display | Yes |
| Portable | Yes |
| Battery Life | 2+ years |
| CO2 Accuracy | ±30 ppm |
| CO2 Range | 0-9999 ppm |
Pros & Cons
Pros
- ✓True NDIR CO2 sensor (not an eCO2 estimate)
- ✓Strong stated accuracy of ±30 ppm
- ✓Multi-parameter monitoring: CO2, Temperature, Humidity, Atmospheric Pressure
- ✓Built-in display for at-a-glance readings
- ✓Excellent battery life (2+ years)
Cons
- ✗Bluetooth only — no remote access when you are away from home
- ✗Premium price compared with entry-level alternatives
Compare this monitor with others using our Monitor Comparison Tool
Frequently Asked Questions
Is the Aranet Aranet4 Pro accurate?+
The Aranet Aranet4 Pro uses a NDIR sensor with a stated accuracy of ±30 ppm over a range of 0-9999 ppm. NDIR is the proven reference technology for consumer CO2 monitoring.
What does the Aranet Aranet4 Pro measure?+
It measures CO2, Temperature, Humidity, Atmospheric Pressure. CO2 is the key metric for judging ventilation — levels below 800 ppm indicate well-ventilated air.
Does the Aranet Aranet4 Pro need WiFi?+
No. The Aranet Aranet4 Pro uses Bluetooth for syncing with the app and shows readings on its built-in display.
Is the Aranet Aranet4 Pro worth it in 2026?+
At $250, the Aranet Aranet4 Pro is a solid choice for professional applications, on-the-go monitoring, classrooms and offices. Its NDIR sensor puts it ahead of cheaper eCO2 estimators. Compare alternatives in our monitor comparison tool before buying.
How long does the Aranet Aranet4 Pro battery last?+
The Aranet Aranet4 Pro runs for 2+ years, and its portable design makes it easy to move between rooms or take when travelling.