MQ series gas sensors are a family of semiconductor-based detection devices renowned for reliability and versatility in gas monitoring. Utilizing SnO₂ as the core sensitive material, these sensors exhibit low conductivity in clean air but rapidly change resistance when exposed to target gases, enabling precise concentration detection.

Available in various models, each targets specific gases: MQ-2 detects smoke and flammable gases (300-10,000 ppm); MQ-3 specializes in alcohol (0.05-10 mg/L); others focus on methane, propane, or toxic gases. Most operate at 5V, offering analog/digital outputs for easy integration with microcontrollers.

Features include fast response (≤10s), quick recovery (≤30s), long lifespan, and low cost. Their compact bakelite/metal encapsulation suits diverse environments. Widely used in home alarms, industrial safety systems, portable detectors, and smart devices, MQ sensors provide essential protection against gas leaks, fire risks, and toxic exposures, making them indispensable for safety and environmental monitoring.

mq-2 Smoke gas sensor

Description

The ADIY MQ2 Smoke gas sensor is an electronic sensor designed to detect the concentration of various gases in the air, including LPG, propane, methane, hydrogen, alcohol, smoke, and carbon monoxide. It operates as a chemiresistor, meaning that its gas detection mechanism is based on the change in resistance of the sensing material when it comes into contact with gas molecules.
The MQ2 is a metal-oxide semiconductor (MOS) type gas sensor. It measures gas concentration using a voltage divider network integrated within the sensor and operates at 5 V DC. It can detect gas concentrations in the range of 200 ppm to 10,000 ppm.
The sensing element consists of an aluminum-oxide-based ceramic substrate coated with tin dioxide (SnO₂), which is sensitive to combustible gases. This element is enclosed within a stainless-steel mesh to protect it from external contamination while allowing gases to diffuse through for accurate measurement.

MQ2 Smoke Sensor Module Features & Specifications

Features	Description
5V Operation	Operates on 5V DC supply
LED Indicators	LEDs for output and power indication
Adjustable Sensitivity	Output sensitivity can be adjusted
Analog Output	0V to 5V analog output range
Digital Output	0V or 5V digital output
Low Cost	Economical and efficient design
Fast Response	Quick signal reaction time
Stable and Long Life	Reliable and durable operation
Dual Output	Supports both digital and analog outputs

mq-3 Alcohol ethanol sensor

Description

The ADIY MQ3 Alcohol Sensor Module utilizes the MQ3 alcohol gas sensor, a low-cost semiconductor device capable of detecting alcohol concentrations ranging from 0.05 mg/L to 10 mg/L. The sensing element is tin dioxide (SnO₂), which exhibits low conductivity in clean air and increased conductivity when exposed to alcohol vapors. The sensor offers high sensitivity to alcohol while maintaining strong resistance to interference from smoke, vapor, and gasoline. It outputs both digital and analog signals, making it easy to interface with microcontrollers such as Arduino or Raspberry Pi.

This sensor is ideal for breath alcohol detection applications, similar to a breathalyzer. It delivers fast response and high sensitivity, with an analog output that varies according to the detected alcohol concentration.

Features

Features: MQ3 Alcohol Sensor Module
5V Operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Good Sensitivity to Alcohol Gas
Both Digital and Analog Outputs

Specifications	MQ3 Alcohol Sensor Module
Concentration	0.05 mg/L ~ 10 mg/L Alcohol
Operating Voltage	5V ±0.1
Current Consumption	150mA
Operation Temperature	-10℃ ~ 70℃

mq-4 Natural gas sensor

Description

Widely employed for gas leak detection in homes and industrial facilities, the MQ4 gas sensor module is specifically engineered to identify gases like methane (CH4) and compressed natural gas (CNG). One of its standout features is rapid responsiveness, and its sensitivity can be tailored to specific requirements through an integrated potentiometer. Belonging to the MQ sensor series, this analog output device is primarily utilized as a CNG sensor, with a core application in measuring the concentration of methane and similar natural gases in the air.

A key operational trait of the MQ4 sensor is its voltage output behavior: as the surrounding gas concentration increases, the sensor’s output voltage also rises accordingly. It operates on a 5V DC power source and has a power consumption of roughly 750mW. Classified as a metal oxide semiconductor (MOS) sensor, it functions by detecting methane gas concentrations in residential or industrial environments and translating these measurements into readable analog voltage signals.

With a sensing range spanning from 300 ppm to 10,000 ppm, the MQ4 sensor is well-suited for effectively identifying gas leaks. This summary outlines the fundamental overview, working principle, and practical applications of the MQ4 methane gas sensor.

Features & Specifications

Features: MQ4 Sensor Module
Sensitivity is good for combustible gas in an extensive range.
High sensitivity for natural gas, methane gas.
Small sensitivity for smoke and alcohol.
Quick responsive, long life and stable.
The drive circuit is simple.
Detection gas is methane or natural.

Specifications	MQ4 Sensor Module
Load resistance	20KΩ
Detecting resistance	10KΩ to 60KΩ
Preheat time	Above 24Hrs
Required voltage	5V
DO output	0.1 to 5V
AO output	0.1 to 0.3V
Operating temperature	14℃ to 122℃

mq-5 Liquefied gas sensor

Description

Engineered for gas leakage detection, the DIY MQ5 gas sensor module is ideal for both residential and industrial setups, specializing in the detection and monitoring of LPG, natural gas, and coal gas. Its core sensitive material is tin dioxide (SnO2), a substance that exhibits low conductivity when exposed to clean air. When combustible target gases are present in the environment, the sensor’s conductivity increases in direct proportion to the gas concentration.

This module offers dual output modes for versatility: an analog output that correlates with the ambient gas concentration, and a user-friendly digital output. An onboard potentiometer allows for precise threshold adjustment—users can set the maximum gas concentration limit, beyond which the digital output is triggered automatically.

Operation is straightforward: simply power the module with a 5V DC supply, calibrate the desired threshold via the potentiometer, and the sensor will immediately start detecting the gas concentration in its surroundings. An integrated LED indicator provides visual feedback, lighting up to signal the presence of target gases.

The digital output enables seamless integration with microcontrollers and various electronic circuits, while the analog output can be connected to a microcontroller’s ADC (Analog-to-Digital Converter) to obtain a broad range of detailed sensor readings.

Features & Specifications

Features
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

mq-6 Liquefied gas sensor

Description

Designed specifically for liquefied petroleum gas (LPG) detection, the DIY MQ6 Gas Sensor Module excels at sensing the concentration of LPG—primarily composed of propane and butane—in the surrounding air. It boasts a detection range spanning 200 to 10,000 ppm, covering the critical concentration levels needed for effective monitoring.

The module features dual output capabilities for flexible usage: an analog output that varies in direct correlation with ambient gas concentration, and a convenient digital output for straightforward triggering. An onboard potentiometer allows users to customize the threshold—setting the maximum gas concentration limit that, when exceeded, activates the digital output.

Operation is remarkably simple: supply the module with a 5V DC power source, adjust the desired threshold via the potentiometer, and it immediately begins detecting LPG concentration in its vicinity. An integrated LED indicator provides clear visual feedback, illuminating whenever target gases are detected.

For seamless integration with electronic systems, the digital output can be easily connected to microcontrollers and other circuits. Meanwhile, the analog output can be linked to a microcontroller’s ADC (Analog-to-Digital Converter), enabling access to a wide spectrum of precise sensor readings for detailed analysis.

Features & Specifications

Features
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

mq-7 Carbon monoxide sensor

Description

The DIY MQ7 Gas Sensor Module offers dual output functionality to meet diverse monitoring needs: an analog output that dynamically correlates with the concentration of target gases in the air, and a user-friendly digital output for straightforward detection alerts. An onboard potentiometer allows for flexible threshold customization—users can set the maximum gas concentration limit, and the digital output will be triggered automatically once this threshold is exceeded.

Operating the module is incredibly simple: just supply it with a 5V DC power source, adjust the desired gas concentration threshold via the potentiometer, and it will immediately start detecting and measuring gas concentrations in its surrounding environment. An integrated LED indicator provides intuitive visual feedback, lighting up promptly whenever target gases are detected.

For seamless integration into electronic projects, the digital output can be easily connected to microcontrollers and various electronic circuits. Meanwhile, the analog output can be linked to a microcontroller’s ADC (Analog-to-Digital Converter), enabling access to a wide range of precise sensor readings for in-depth concentration analysis.

Features & Specifications

Features: Gas Sensor Module MQ7 – ADIY
Sensitive for carbon monoxide
Output voltage boosts along with the concentration of the measured gases increases
Fast response and recovery
Adjustable sensitivity
Signal output indicator

Specifications: Gas Sensor Module MQ7 – ADIY
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

mq-8 Hydrogen gas sensor

Description

As a user-friendly hydrogen detection solution, the DIY MQ8 Hydrogen Sensor Module is specifically designed for sensing hydrogen gas concentrations in the ambient air. It features a detection range of 100 to 10,000 ppm, covering the key concentration levels required for effective hydrogen monitoring.

The module comes equipped with dual output modes for versatile application: an analog output that varies proportionally with the hydrogen concentration in the air, and a convenient digital output for quick alert triggering. An onboard potentiometer allows users to flexibly set the threshold—defining the maximum hydrogen concentration that, when surpassed, activates the digital output.

Operation is remarkably straightforward: supply the module with a 5V DC power source, adjust the desired concentration threshold via the potentiometer, and it will immediately begin detecting and measuring hydrogen levels in its surroundings. An integrated LED indicator offers clear visual feedback, illuminating as soon as hydrogen gas is detected.

For seamless integration into electronic systems and projects, the digital output can be easily connected to microcontrollers and other electronic circuits. Meanwhile, the analog output can be linked to a microcontroller’s ADC (Analog-to-Digital Converter), enabling access to a wide spectrum of precise sensor readings for detailed concentration analysis.

Features & Specifications

Features & Specifications of MQ8 Hydrogen H2 Gas Sensor Module
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

mq-9 Flammable gas sensor Module

Description

Engineered for gas leakage detection in both residential and industrial settings, the DIY MQ9 Gas Sensor Module is highly versatile—capable of detecting key gases including LPG, carbon monoxide (CO), and methane (CH4). A core operational trait of this sensor is its conductivity response: as the concentration of target gases increases, the sensor’s conductivity rises proportionally.

The module offers dual output modes to suit diverse application needs: an analog output that dynamically correlates with ambient gas concentration, and a user-friendly digital output for straightforward alert triggering. An onboard potentiometer enables flexible threshold customization, allowing users to set the maximum gas concentration limit that, when exceeded, activates the digital output automatically.

Operation is exceptionally simple: supply the module with a 5V DC power source, adjust the desired concentration threshold via the potentiometer, and it immediately begins detecting and measuring gas levels in its surrounding environment. An integrated LED indicator provides intuitive visual feedback, lighting up promptly whenever target gases are detected.

For seamless integration into electronic projects and systems, the digital output can be easily connected to microcontrollers and various electronic circuits. Meanwhile, the analog output can be linked to a microcontroller’s ADC (Analog-to-Digital Converter), enabling access to a wide range of precise sensor readings for in-depth concentration analysis.

Features & Specifications

Features & Specifications: MQ9 Gas Sensor Module
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

mq-135 Air quality sensor Module

Description

Crafted with the MQ135 air quality sensor as its core, the MQ135 Gas Sensor Module is a cost-effective semiconductor device designed for multi-gas detection. It boasts high sensitivity to ammonia, sulfides, and benzene series vapors, while also delivering reliable monitoring of smoke and other toxic gases in the environment.

Classified as a Metal Oxide Semiconductor (MOS) gas sensor—also referred to as chemoresistors—its detection principle relies on changes in the resistance of the sensing material when it comes into contact with target gases. By leveraging a simple voltage divider network, the module can effectively detect and quantify gas concentrations in its surroundings.

Equipped with both digital and analog output modes, the MQ135 module offers flexible integration options. It can be seamlessly connected to a range of devices including microcontrollers, Arduino boards, and Raspberry Pi, making it suitable for diverse air quality monitoring projects and applications.

Features & Specifications

Features – MQ135 Gas Sensor Module
Wide detecting scope
Fast response and High sensitivity
Stable and long-life Simple drive circuit
Used in air quality control equipment for buildings/offices, suitable for detecting NH3, NOx, alcohol, Benzene, smoke, CO2, etc.
Size: 35mm × 22mm × 23mm (length × width × height)
Signal output instruction
Dual signal output (analog output, and high/low digital output)
0.8 ~ 4.2V analog output voltage, the higher the concentration the higher the voltage

Specifications – MQ135 Gas Sensor Module
Operating Voltage	2.5V to 5.0V
Power Consumption	150mA
Detect / Measure	NH3, NOx, CO2, Alcohol, Benzene, Smoke
Typical Operating Voltage	5V
Digital Output	0V to 5V (TTL Logic) @ 5V Vcc
Analog Output	0~5V @ 5V Vcc

Shipping Cost

We only ship to the United States. Shipping costs are calculated based on the total order amount.

Shipping Method And Delivery Time

All orders will be processed and shipped within 72 hours of placing the order (excluding weekends and holidays). They will ship from Shenzhen, China, primarily via 4PX logistics. Depending on the destination and logistics conditions, other carriers such as DHL, FedEx, UPS, USPS, etc., may also handle the delivery. Estimated shipping time is 7-12 business days, with actual delivery occurring in 10-17 business days, depending on logistics conditions.

Payment:

We accept Visa, Master card, Maestro, American Express, JCB, Dinner's Club, Discover, Paypal, Apple Pay, Google Pay .

Click to enlarge

MQ Gas Sensor Module

Price range: $2.99 through $3.001pcs

Dimensions	N/A
Brand	easyelecmodule

specification

MQ-135 Air quality sensor

MQ-2 Smoke gas sensor

MQ-3 Alcohol ethanol sensor

MQ-4 Natural gas sensor

MQ-5 Liquefied gas sensor

MQ-6 Application scenario

MQ-7 Carbon monoxide sensor

MQ-8 Hydrogen gas sensor

MQ-9 Flammable gas sensor

Add to wishlist

SKU: N/A Category: Modules

DESCRIPTIONS AND FEATURES

Features	Description
5V Operation	Operates on 5V DC supply
LED Indicators	LEDs for output and power indication
Adjustable Sensitivity	Output sensitivity can be adjusted
Analog Output	0V to 5V analog output range
Digital Output	0V or 5V digital output
Low Cost	Economical and efficient design
Fast Response	Quick signal reaction time
Stable and Long Life	Reliable and durable operation
Dual Output	Supports both digital and analog outputs

Features: MQ3 Alcohol Sensor Module
5V Operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Good Sensitivity to Alcohol Gas
Both Digital and Analog Outputs

Specifications	MQ3 Alcohol Sensor Module
Concentration	0.05 mg/L ~ 10 mg/L Alcohol
Operating Voltage	5V ±0.1
Current Consumption	150mA
Operation Temperature	-10℃ ~ 70℃

Features: MQ4 Sensor Module
Sensitivity is good for combustible gas in an extensive range.
High sensitivity for natural gas, methane gas.
Small sensitivity for smoke and alcohol.
Quick responsive, long life and stable.
The drive circuit is simple.
Detection gas is methane or natural.

Specifications	MQ4 Sensor Module
Load resistance	20KΩ
Detecting resistance	10KΩ to 60KΩ
Preheat time	Above 24Hrs
Required voltage	5V
DO output	0.1 to 5V
AO output	0.1 to 0.3V
Operating temperature	14℃ to 122℃

Features
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

Features
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

Features: Gas Sensor Module MQ7 – ADIY
Sensitive for carbon monoxide
Output voltage boosts along with the concentration of the measured gases increases
Fast response and recovery
Adjustable sensitivity
Signal output indicator

Specifications: Gas Sensor Module MQ7 – ADIY
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

Features & Specifications of MQ8 Hydrogen H2 Gas Sensor Module
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

Features & Specifications: MQ9 Gas Sensor Module
5V operation
LEDs for output and power
Output sensitivity adjustable
Analog output 0V to 5V
Digital output 0V or 5V
Low Cost
Fast Response
Stable and Long Life
Both Digital and Analog Outputs

Features – MQ135 Gas Sensor Module
Wide detecting scope
Fast response and High sensitivity
Stable and long-life Simple drive circuit
Used in air quality control equipment for buildings/offices, suitable for detecting NH3, NOx, alcohol, Benzene, smoke, CO2, etc.
Size: 35mm × 22mm × 23mm (length × width × height)
Signal output instruction
Dual signal output (analog output, and high/low digital output)
0.8 ~ 4.2V analog output voltage, the higher the concentration the higher the voltage

Specifications – MQ135 Gas Sensor Module
Operating Voltage	2.5V to 5.0V
Power Consumption	150mA
Detect / Measure	NH3, NOx, CO2, Alcohol, Benzene, Smoke
Typical Operating Voltage	5V
Digital Output	0V to 5V (TTL Logic) @ 5V Vcc
Analog Output	0~5V @ 5V Vcc