🔍 Product Overview

The MQ-135 Air Quality Sensor Module is designed to detect a variety of harmful gases and air pollutants, including ammonia (NH₃), nitrogen oxides (NOx), alcohol, benzene, smoke, carbon dioxide (CO₂) and volatile organic compounds (VOCs). Its compact breakout format makes it ideal for integrating into air quality monitors, ventilation systems, or environmental sensing projects.

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🚀 Why It’s Ideal for Your Projects

• Wide­-range pollutant detection — Sensitive to several common indoor and outdoor air contaminants, so you can build smarter ventilation, safety or environmental monitoring systems.

• Dual output flexibility — Offers both analog output for measuring relative gas concentration and a digital output with adjustable threshold for alarm or trigger activation.

• Microcontroller-friendly integration — Operates on a 5 V supply and connects easily to boards such as Arduino, ESP32, Raspberry Pi (via ADC) and other microcontroller platforms.

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📝 Key Features

• Detects gases including ammonia, benzene, smoke, NOx, CO₂ and other pollutants.

• Outputs: analog voltage proportional to gas concentration, and digital TTL output when concentration exceeds a set threshold.

• Operating voltage: typically 5 V DC.

• Adjustable sensitivity through onboard potentiometer to fine-tune the digital trigger level.

• Requires a warm-up period for stable readings and consistent performance.

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🎯 Typical Applications

• Indoor air-quality monitors – Keep tabs on pollutants in homes, offices, classrooms or labs.

• Ventilation and HVAC control – Trigger fans or systems based on rising pollutant gases.

• IoT environmental tracking – Integrate the sensor into connected systems for logging and remote alerts of air-quality changes.

• Educational and hobbyist builds – Ideal for learning about gas sensing, analog vs digital outputs and microcontroller interfacing.

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✅ Why You’ll Love It

The MQ-135 module brings affordability, versatility and ease-of-use to air-quality monitoring. It’s perfect whether you’re prototyping a teaching demo, building a smart-home air sensor, or integrating gas-detection into a larger system — giving you flexible outputs, broad detection and straightforward microcontroller compatibility.