MQ-3 Gas Sensor Module For Benzine, CH4, Hexane, LPG, CO Detector Module

The MQ-3 Gas Sensor Module is a high-sensitivity semiconductor gas detection module specifically designed to detect alcohol (ethanol) vapors in the surrounding air. Based on the MQ-3 Metal Oxide Semiconductor (MOS) gas sensor, the module is widely used in alcohol detection systems, breath analyzers, industrial safety equipment, vehicle safety systems, laboratory experiments, smart monitoring devices, and IoT-based gas sensing applications.

The MQ-3 sensor offers excellent sensitivity to ethanol while also responding to other alcohol vapors. It provides both analog and digital outputs, allowing it to be used for continuous alcohol concentration monitoring as well as threshold-based detection. The analog output generates a voltage proportional to the detected alcohol vapor concentration, while the digital output changes state when the alcohol level exceeds a user-defined threshold set using the onboard sensitivity adjustment potentiometer.

Operating from a standard 5V DC supply, the MQ-3 module is fully compatible with Arduino, ESP32, ESP8266, Raspberry Pi (with an external ADC for analog readings), STM32, PIC, AVR, ATmega, NodeMCU, and other popular microcontroller platforms. Its compact PCB design, stable performance, fast response, and long operational life make it suitable for students, hobbyists, engineers, researchers, and industrial developers.

The MQ-3 Gas Sensor Module is widely used in alcohol detection systems, driver safety monitoring, laboratory testing, smart home automation, industrial monitoring, educational electronics, and embedded system development.

Working Principle

The MQ-3 sensor operates using Metal Oxide Semiconductor (MOS) sensing technology. The sensing element consists of a tin dioxide (SnO₂) layer heated to its operating temperature by an internal heating element.

When alcohol (ethanol) vapor comes into contact with the heated sensing surface, the electrical resistance of the sensing material changes according to the concentration of alcohol present in the surrounding air.

The onboard signal conditioning circuit converts this resistance variation into an analog voltage that can be measured by a microcontroller. An integrated comparator continuously compares the sensor signal with a preset threshold and generates a digital HIGH or LOW output whenever the alcohol concentration exceeds the selected level.

The onboard potentiometer allows easy adjustment of the detection sensitivity and threshold according to the application requirements.

Key Features

High sensitivity to alcohol (ethanol) vapors.

Based on the MQ-3 Metal Oxide Semiconductor gas sensor.

Optimized for alcohol detection applications.

Analog output for continuous alcohol concentration monitoring.

Digital output with adjustable detection threshold.

Onboard sensitivity adjustment potentiometer.

Fast response and recovery time.

Stable and reliable performance.

Long operational lifespan.

Operating voltage of 5V DC.

Low power consumption.

Compact PCB design.

Built-in power and detection indicator LEDs.

Compatible with Arduino, ESP32, ESP8266, Raspberry Pi (with external ADC), STM32, PIC, AVR, ATmega, NodeMCU, and PLC systems.

Suitable for educational, industrial, commercial, and DIY electronics projects.

Technical Specifications

Sensor Type: Metal Oxide Semiconductor (MOS)

Sensor IC: MQ-3

Operating Voltage: 5V DC

Output Type: Analog (AO) and Digital (DO)

Detection Method: Alcohol Vapor Concentration Sensing

Primary Detectable Gas: Alcohol (Ethanol) Vapor

Sensitivity Adjustment: Onboard Potentiometer

Response Time: Fast

Recovery Time: Fast

Power Consumption: Low

Interface: VCC, GND, AO, DO

Status Indicators: Power LED and Detection LED

Operating Temperature: Suitable for standard indoor operating environments

Module Type: Alcohol Gas Sensor

Applications

Alcohol vapor detection.

Breath analyzer prototypes.

Driver safety monitoring systems.

Industrial alcohol leak detection.

Laboratory experiments.

Smart home automation.

Environmental monitoring.

IoT gas monitoring systems.

Safety and warning systems.

Educational electronics projects.

Research and laboratory testing.

Robotics and automation.

DIY electronics and prototype development.

Embedded system development.

Alcohol detection equipment.