Description

SONOFF AirGuard TH SNZB-02DR2 ZigBee LCD Temperature and Humidity Sensor

The SONOFF AirGuard TH SNZB-02DR2 is a smart indoor temperature and humidity sensor with a large 3.6" LCD display, precise Sensirion SHT40 measurement technology, and support for both ZigBee 3.0 and Bluetooth connectivity. Designed for smart homes and accurate indoor climate monitoring, it combines professional-grade measurement accuracy with practical everyday usability.

The display provides clear real-time readings of temperature, humidity, daily minimum and maximum values, comfort level indicators, battery status and optional remote sensor data. When connected to a ZigBee gateway, the device supports automation scenarios, remote monitoring, notifications and long-term historical statistics.

The AirGuard TH can also operate directly with a smartphone via Bluetooth without requiring a ZigBee hub, making it suitable both for simple standalone monitoring and advanced smart home systems.

Key Features

• Large 3.6" high-contrast LCD display
• Precise Sensirion SHT40 sensor
• ZigBee 3.0 and Bluetooth dual connectivity
• Real-time temperature and humidity monitoring
• Daily minimum and maximum value display
• Comfort level indicator
• Dew point and VPD analysis in app
• Smart home automation support
• Historical data logging and graphs
• Supports remote sensor comparison display
• Battery-powered operation with low power consumption
• Compatible with Home Assistant, Zigbee2MQTT and SmartThings

Aim of the Product

The AirGuard TH is designed to monitor indoor climate conditions accurately and help users maintain a healthier and more comfortable environment. It supports smart automation systems for temperature and humidity control while also functioning as a standalone monitoring device.

Applications

• Smart home climate monitoring
• Bedroom and children's room monitoring
• Greenhouse and plant humidity management
• Wine and food storage monitoring
• Office and warehouse climate control
• Mold and moisture prevention
• Ventilation and humidifier automation
• Indoor environmental analysis

Large 3.6" LCD Display

The large high-definition LCD screen allows temperature and humidity readings to be checked instantly from a distance. The display simultaneously shows:

• Current temperature
• Current humidity
• 24-hour minimum and maximum values
• Comfort level indicator
• Battery status
• Bluetooth and ZigBee connection status
• Optional remote sensor data

According to the manufacturer manual, the display is designed for quick readability and real-time environmental monitoring. 

High Precision Sensirion SHT40 Sensor

The AirGuard TH uses the professional Sensirion SHT40 sensor for highly stable and accurate measurements.

• Temperature accuracy: ±0.2°C
• Humidity accuracy: ±2% RH
• Temperature resolution: 0.1°C / 0.1°F
• Humidity resolution: 1% RH on display, 0.1% RH in app

The precise readings help optimize comfort, reduce excessive humidity and improve air quality management.

ZigBee 3.0 and Bluetooth Connectivity

The sensor supports both ZigBee 3.0 and Bluetooth operation.

• ZigBee mode: full smart home functionality including automation, notifications and remote access
• Bluetooth mode: direct local smartphone connection without gateway

The dual-mode operation allows flexible deployment depending on the user's smart home setup.

Smart Home Compatibility

The AirGuard TH integrates with multiple smart home ecosystems and platforms.

• SONOFF eWeLink ecosystem
• Home Assistant
• Zigbee2MQTT
• SmartThings
• Alexa
• Google Home
• Matter Bridge environments

The device can be used in automations such as:

• Turning on humidifiers when humidity drops
• Activating ventilation when humidity becomes excessive
• Switching heating or cooling devices based on room temperature
• Environmental monitoring alerts

Data Logging and Analytics

The eWeLink application stores detailed historical statistics and graphs for up to approximately six months.

• Daily, weekly and long-term statistics
• Min/max values
• Average values
• Dew point analysis
• VPD (Vapor Pressure Deficit) analysis
• Comfort level monitoring

This allows users to identify long-term climate trends and optimize indoor conditions more effectively.

Remote Temperature and Humidity Display

When connected to compatible SONOFF ZigBee gateways, the display can show data from other supported SONOFF sensors located in different rooms.

Supported remote sensors include:

• SNZB-02
• SNZB-02P
• SNZB-02D
• SNZB-02WD
• SNZB-02LD

The feature allows fast room-to-room temperature comparison directly on the display without opening the mobile app. 

Installation and Power

The AirGuard TH can be placed on a table using the integrated stand or mounted on a wall.

• Desktop stand included
• Wall mounting possible
• Powered by 2 × AAA batteries
• Low power consumption design

Package Contents

• SONOFF AirGuard TH SNZB-02DR2 sensor
• User manual

Technical Specifications

Safety Information

• Indoor use only
• Do not expose to condensation or direct water contact
• Keep batteries away from children
• Do not short-circuit batteries
• Do not recharge non-rechargeable batteries
• Replace batteries only with identical battery types
• Dispose of electronic waste according to local regulations

Other Useful Information

The AirGuard TH supports configurable reporting intervals and reporting thresholds, allowing users to optimize battery life and update frequency based on their requirements.

According to the manufacturer, the default reportable temperature change is ±0.2°C and humidity change is ±1% RH, with adjustable reporting intervals from 5 seconds to 1 hour.

The device firmware can be updated for additional functions and improved compatibility. Remote temperature display support requires firmware version 1.1.0 or newer. 

Glossary

• ZigBee 3.0: Low-power wireless communication protocol for smart home devices
• Bluetooth Proximity Mode: Direct local smartphone connection without gateway
• Dew Point: Temperature at which moisture condenses from the air
• VPD: Vapor Pressure Deficit, used to analyze humidity conditions for plants and indoor environments
• SHT40: Professional-grade Sensirion temperature and humidity sensor

FAQ

Downloads and Manuals

• Official user manual (PDF)

Manufacturer & GPSR Information

Manufacturer:
Shenzhen Sonoff Technologies Co., Ltd.
Bulong Road A
518000 Shenzhen
China
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

EU Responsible Entity:
SONOFF TECHNOLOGY Deutschland GmbH
Breite Str. 22
40213 Düsseldorf
Germany
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.