SONOFF AirGuard TH Pressure
SONOFF AirGuard TH Pressure
SONOFF AirGuard TH Pressure (SNZB-02M) is a next-generation environmental sensor that goes far beyond standard climate monitoring. While basic sensors only monitor temperature and humidity, the SNZB-02M adds a highly accurate air pressure sensor. By combining these three measurements in real time, it automatically calculates the Dew Point and Vapor Pressure Deficit (VPD), giving you a complete, professional picture of your indoor environment.
Key Features
-
5-in-1 Climate Monitoring: Measures temperature, relative humidity, and barometric pressure. Using these readings, the app instantly calculates the dew point (to warn you before condensation forms on walls, which causes mold) and VPD (the best metric for optimizing plant growth in indoor greenhouses).
-
Ultra-fast 5-second refresh rate: Unlike older sensors that report data only every few minutes to save battery, the SNZB-02M updates its readings every 5 seconds. You will know immediately when a window is opened, when a bathroom gets steamy, or when a humidor loses humidity.
-
Weather Trend Forecasting: By monitoring air pressure (700 to 1100 hPa), you can build smart home automations that react to weather changes before they even happen. A rapid drop in pressure can trigger notifications to close skylights before a storm.
-
High Precision: Delivers professional-grade accuracy with deviations of only ±0.2 °C for temperature, ±2% RH for humidity, and ±0.1 hPa for air pressure.
-
2-Year Battery Life: Despite the rapid 5-second refresh rate, the sensor uses an ultra-efficient EFR32MG22 Zigbee chip and a massive CR2477 coin cell battery, ensuring over two years of continuous operation.
-
Universal Zigbee 3.0 Compatibility: Integrates seamlessly into local smart home platforms such as Home Assistant (via ZHA or Zigbee2MQTT), eWeLink, and SmartThings.
Technical Specifications
| Feature | Specification |
| Model | SNZB-02M (AirGuard Series) |
| Wireless Protocol | Zigbee 3.0 (IEEE 802.15.4) |
| Measured Values | Temperature, humidity, air pressure |
| Calculated Values | Dew point, vapor pressure deficit (VPD) |
| Temperature Range / Accuracy | -20 °C to +60 °C / ±0.2 °C |
| Humidity Range / Accuracy | 5% to 95% RH (non-condensing) / ±2% RH |
| Pressure Range / Accuracy | 700 to 1100 hPa / ±0.1 hPa |
| Data Refresh Rate | Every 5 seconds |
| Power Supply | 1x CR2477 3V battery (included) |
| Estimated Battery Life | > 2 years |
| Platform Compatibility | Home Assistant, Zigbee2MQTT, ZHA, eWeLink, SmartThings |
| Dimensions | 45 mm × 45 mm × 17.6 mm |
| Weight | 27.3 g (including battery) |
| Housing Material | White polycarbonate (PC) |
Package Contents
-
SONOFF AirGuard TH Pressure Sensor (SNZB-02M)
-
1x CR2477 battery (pre-installed)
-
3M double-sided adhesive mounting pad
-
Quick Start Guide