Joy-it MQ135V2 Gas Sensor Module for Air Quality Detection

Monitor air quality in real time with the Joy-it MQ135V2 gas sensor module. This compact semiconductor sensor detects a wide range of harmful gases, including ammonia (NH3), nitrogen oxides (NOx), alcohol, benzene, smoke, and carbon dioxide (CO2). It is ideal for indoor air quality monitoring, safety systems, and DIY environmental projects. The module operates on 5V DC and provides both analog and digital outputs, making it compatible with Arduino, Raspberry Pi, and other microcontroller platforms. With an onboard potentiometer, you can adjust sensitivity to suit your specific application. The sensor responds quickly and recovers fast, ensuring reliable performance in dynamic environments.

Key specifications

• Sensor type: Semiconductor (tin dioxide SnO2)
• Detected gases: NH3, NOx, alcohol, benzene, smoke, CO2, and more
• Operating voltage: 5V DC
• Output: Analog (0-5V) and digital (TTL)
• Detection ranges: NH3/benzene/alcohol 10-1000 ppm, CO2 10-300 ppm, smoke 10-100 ppm
• Response time: ≤10 seconds; recovery time: ≤30 seconds
• Operating temperature: -10°C to 50°C; humidity ≤95% RH non-condensing
• Interface: 4-pin header (VCC, GND, DOUT, AOUT)
• Adjustable sensitivity via potentiometer
• Heater consumption: approx. 150 mA

Why choose it

The MQ135V2 offers a cost-effective solution for multi-gas detection. Its dual output allows flexible integration: use the analog output for precise concentration readings or the digital output for simple threshold-based alarms. The sensor's wide detection range and fast response make it suitable for both hobbyist and professional projects. The onboard potentiometer enables fine-tuning without additional components, saving time and effort.

Ideal use cases

• Indoor air quality monitoring stations
• Safety alarms for harmful gas leaks
• Environmental sensing for smart home systems
• Educational projects and STEM learning
• Industrial emission monitoring (preliminary screening)

Good to know

The sensor requires a preheat time of about 20 seconds before stable readings. It is designed for non-condensing environments and should be stored within -20°C to 70°C. The module is not waterproof and should be protected from direct moisture. Always ensure proper ventilation when testing gases. The package includes one sensor module; no additional cables or mounting hardware are included.