MQ135 Air Quality Gas Sensor Module

The MQ135 Air Quality Gas Sensor Module is a versatile environmental sensing board designed to detect various harmful gases and monitor overall air quality. It is based on the MQ-135 gas sensor and responds to gases such as ammonia (NH₃), nitrogen oxides (NOₓ), alcohol, benzene, smoke, CO₂ and other harmful air pollutants. The module provides analog output that varies with gas concentration, making it easy to interface with microcontrollers like Arduino, ESP, PIC, and Raspberry Pi (with ADC).

This sensor is ideal for indoor air quality monitoring systems, smart home devices, HVAC control, environmental sensing projects, and safety alert applications. The onboard potentiometer allows sensitivity adjustment to fine-tune response levels for different environments.

KEY FEATURES

• Detects harmful gases and air quality changes
• Analog voltage output proportional to gas concentration
• Adjustable sensitivity via onboard potentiometer
• Simple interface for microcontroller integration
• Low cost and compact design
• Suitable for air quality monitoring and safety systems

SPECIFICATIONS

• Sensor Model MQ135
• Target Gases NH₃, NOₓ, alcohol, benzene, smoke, CO₂ and air quality
• Output Type Analog voltage
• Operating Voltage 5V DC
• Response Time Fast gas detection
• Sensitivity Adjustable

INTERFACES



• VCC Power supply
• GND Ground
• AO Analog output voltage