MQ-135 Gas Sensor Module

The MQ-135 Gas Sensor is a widely used air-quality sensor designed to detect harmful gases and pollutants in the environment. It is sensitive to gases such as ammonia (NH₃), nitrogen oxides (NOx), benzene, smoke, alcohol, and carbon dioxide (CO₂), making it ideal for indoor air-quality monitoring and pollution detection projects.

This module comes with an onboard LM393 comparator, providing both analog and digital outputs, which makes it easy to interface with microcontrollers like Arduino, Raspberry Pi, ESP8266, and ESP32.

Key Features

• Detects a wide range of gases and air pollutants

• Sensitive to NH₃, NOx, CO₂, benzene, smoke, and alcohol

• Provides Analog (A0) and Digital (D0) output

• Adjustable sensitivity using onboard potentiometer

• Fast response and high sensitivity

• Long life and stable performance

• Compatible with 3.3V and 5V systems

Technical Specifications

• Operating Voltage: 5V DC

• Output Type: Analog & Digital

• Detection Gases: NH₃, NOx, CO₂, smoke, alcohol, benzene

• Heater Resistance: ~33Ω

• Preheat Time: 20–30 seconds (recommended)

• Interface: Breadboard-friendly pin layout

Applications

• Air quality monitoring systems

• Indoor pollution detection

• Smart home and HVAC systems

• Gas leakage detection projects

• IoT environmental monitoring

• Industrial and safety equipment

• Educational and DIY electronics projects

Why Choose MQ-135?

• Ideal for air quality and pollution monitoring

• Easy to use with microcontrollers

• Cost-effective solution for gas sensing projects

• Suitable for beginners, students, and professionals

Package Includes

• 1 × MQ-135 Gas Sensor Module