MQ-135 Gas Sensor Module – Air Quality, NH₃, CO₂, Alcohol, Benzene, and Smoke Detection

The MQ-135 Gas Sensor Module is a widely used air quality sensor designed for detecting a variety of harmful gases such as ammonia (NH₃), carbon dioxide (CO₂), alcohol, benzene, smoke, and other volatile organic compounds (VOCs). It is highly suitable for air pollution monitoring, gas leak detection systems, and smart environment projects. The module provides both analog and digital outputs, making it easy to interface with Arduino, ESP32, Raspberry Pi, and other microcontrollers.

Key Features:

Multi-Gas Detection: Capable of detecting a wide range of gases including NH₃, CO₂, alcohol, benzene, and smoke.
High Sensitivity and Stability: Provides reliable and accurate gas detection for indoor and outdoor environments.
Analog and Digital Outputs: Analog output for precise gas concentration measurement, digital output with threshold setting.
Adjustable Threshold: On-board potentiometer to calibrate the digital output sensitivity.
Compact and Easy to Use: Standard 4-pin interface for easy integration into embedded systems.

Product Specifications:

Feature	Specification
Operating Voltage	5V DC
Detection Gases	NH₃, CO₂, Benzene, Alcohol, Smoke, VOCs
Output Type	Analog & Digital
Digital Output Threshold	Adjustable via on-board potentiometer
Sensitivity Range	10 – 1000 ppm (depending on gas type)
Preheat Time	20 seconds (minimum)
Operating Temperature	-10°C to +50°C
Dimensions	Approx. 32mm x 20mm x 22mm