MQ 8 Gas Sensor Module Hydrogen Detection

AED 19.95



The MQ-8A sensor module is an exceptional Metal Oxide Semiconductor (MOS) sensor designed for precise and reliable detection of hydrogen gas. the MQ-8 gas sensor module encompasses a powerful combination of features, including high sensitivity to combustible gases, fast response time, easy positioning, long lifespan, low cost, simple drive circuit, and versatility in output options. With its ability to detect hydrogen gas concentrations in the range of 100 to 1000ppm, it serves as a reliable tool for diverse gas detection applications, delivering enhanced safety and peace of mind. different settings.


Package Includes:

  • 1x MQ8 H2 Sensor Module



  • High Sensitivity: The module exhibits good sensitivity to combustible gases over a wide range, allowing for reliable detection of various gases.
  • Fast Response Time: It quickly responds to changes in gas concentrations, enabling prompt detection and response to potential gas hazards.
  • Easy Positioning: The module is designed with four screw holes, making it easy to position and install in different applications.
  • Long Life: With durable construction, the module offers a long lifespan, ensuring consistent and reliable gas detection over extended periods.
  • Low Cost: The MQ-8 module provides cost-effective gas detection capabilities without compromising performance.
  • Simple Drive Circuit: It features a straightforward drive circuit, simplifying the integration process into existing systems.
  • Operating Voltage: The module operates on a 5V DC power supply, making it compatible with standard power sources.
  • Gas Detection: The MQ-8 module specifically detects hydrogen gas concentrations in the air, allowing for targeted gas monitoring.
  • Resistance to Other Gases: It also exhibits resistance to other gases, such as LPG, smoke, and alcohol, expanding its versatility in different environments.
  • Heater Power Consumption: The module's heater consumes less than 800mW of power, ensuring energy efficiency.
  • Detection Range: The MQ-8 module can detect hydrogen gas concentrations in the range of 100 to 1000 parts per million (ppm), providing precise measurements.
  • Digital or Analog Output: It can be used as a digital or analog sensor, offering flexibility in output options based on the requirements of the application.
  • Adjustable Sensitivity: The sensitivity of the digital pin can be varied using the built-in potentiometer, allowing for customization of detection levels.



The MQ-8 gas sensor module is a remarkable solution that combines exceptional features for efficient and cost-effective gas detection. With its high sensitivity to combustible gases over a wide range, it provides reliable detection in various environments. The module boasts an impressively fast response time, allowing for quick identification and response to potential gas hazards. Positioning the MQ-8 module is a breeze, thanks to the four screw holes that enable easy installation and placement. Its longevity and low cost make it a practical choice for long-term gas detection needs. The module operates on a 5V DC power supply, ensuring compatibility with standard power sources. The MQ-8 module excels in detecting hydrogen gas concentrations in the air, while also exhibiting resistance to LPG, smoke, and alcohol. This versatility enhances its usability in diverse applications, from industrial settings to residential environments. With its simple drive circuit, the MQ-8 module offers straightforward integration into existing systems. Its heater power consumption is impressively low, consuming less than 800mW of power. The module provides flexibility in output options, allowing for digital or analog operation. Additionally, the sensitivity of the digital pin can be easily adjusted using the built-in potentiometer, providing customizable detection levels to suit specific requirements.


Principle of Work:

  • The MQ-8 gas sensor operates based on the principle of Metal Oxide Semiconductor (MOS) gas sensing. It consists of a sensing element composed of a metal oxide film that reacts to the presence of specific gases, such as hydrogen. The film's electrical conductivity changes when it interacts with the target gas, leading to measurable variations in the sensor's output.
  • As a module, the MQ-8 sensor integrates this sensing element with additional components to provide convenient and user-friendly gas detection capabilities. The module typically includes an onboard circuitry responsible for signal processing and output generation.
  • The module has 2 LEDs, analog, and digital outputs, the module incorporates these features to facilitate different modes of operation and provide visual indications of the sensor's status:
  1. LED Power Indicator: The module includes an LED power indicator to show that the sensor is receiving power and functioning properly. When the LED is illuminated, it indicates that the module is operational.

  2. Analog Output: The module offers an analog output, usually in the form of a voltage signal, which provides continuous information about the detected gas concentration. The analog output can be connected to an analog-to-digital converter (ADC) or microcontroller for further processing or data logging.

  3. Digital Output: The module also provides a digital output that typically operates as a digital switch. The digital output transitions between logic high and logic low states are based on a predetermined threshold set for gas concentration. It can be connected directly to a microcontroller or digital input pin, allowing for simple integration and triggering of actions based on gas detection.

Adjusting the sensitivity of the MQ-8 module done by the potentiometer, a variable resistor, which is used to adjust the sensitivity. It is located on the module itself. To adjust the sensitivity, you can use a small screwdriver or similar tool to rotate the potentiometer. The potentiometer is designed to be easily accessible for manual adjustment. By turning the potentiometer clockwise or counterclockwise, you can increase or decrease the sensitivity of the digital pin output. This adjustment affects the gas concentration level at which the digital output transitions between high and low states.


Pinout of the Sensor:

Pin No:

Pin Name:




This pin powers the module, typically the operating voltage is +5V



Used to connect the module to system ground


Digital Out

You can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer


Analog Out

This pin outputs 0-5V analog voltage based on the intensity of the gas 



  1. Gas Leak Detection: The MQ-8 module is widely used for detecting hydrogen gas leaks in industrial settings, including manufacturing plants, refineries, and chemical facilities. It helps ensure early detection and timely response to prevent accidents and ensure worker safety.
  2. Fuel Cell Monitoring: Hydrogen fuel cells are used in clean energy applications. The MQ-8 module can be utilized to monitor hydrogen gas levels in fuel cells, ensuring optimal operation and safety.
  3. Hydrogen Storage Facilities: Facilities that store hydrogen gas, such as hydrogen refueling stations or hydrogen storage tanks, benefit from the MQ-8 module's ability to monitor gas concentrations and detect any leaks or safety hazards.
  4. Laboratory Safety: Laboratories that handle hydrogen gas for experiments or research rely on gas sensors like the MQ-8 module to maintain a safe environment by detecting any potential leaks or buildup of hydrogen gas.
  5. Fire Protection Systems: The presence of hydrogen gas can increase the risk of fire. Integrating the MQ-8 module into fire protection systems allows for the early detection of hydrogen gas, triggering appropriate safety measures and minimizing fire hazards.
  6. Residential and Commercial Gas Safety: The MQ-8 module can be incorporated into residential or commercial gas detection systems to monitor hydrogen gas levels, ensuring the safety of occupants and preventing potential gas-related accidents.
  7. Industrial Processes: In various industrial processes where hydrogen gas is used, such as chemical reactions or hydrogenation processes, the MQ-8 module can provide continuous monitoring to maintain optimal working conditions and prevent hazardous situations.
  8. Environmental Monitoring: The MQ-8 module can contribute to environmental monitoring efforts, such as detecting hydrogen gas emissions from landfills or industrial sites, aiding in pollution control and compliance with environmental regulations.



  • Connect the GND pin of the MQ8 sensor to the GND pin of the Arduino board.
  • Connect the VCC pin of the MQ8 sensor to the +5V power source pin of the Arduino board.
  • Connect the A-out pin of the MQ8 sensor to the Analog pin A0 of the Arduino board.



This Module doesn't need any Library to function.



This example code reads the analog value from the sensor and prints it to the serial monitor. It controls an LED based on the sensor value: 

#define MQ8pin A0
float sensorValue; // variable to store sensor value

void setup() {
  pinMode(13, OUTPUT);
  Serial.begin(9600); // sets the serial port to 9600
  Serial.println("MQ8 warming up!");
  delay(20000); // allow the MQ8 to warm up

void loop() {
  sensorValue = analogRead(MQ8pin); // read analog input pin A0
  Serial.print("Sensor Value: ");
  if (sensorValue > 400) {
    digitalWrite(13, HIGH);
  } else {
    digitalWrite(13, LOW);
  delay(2000); // wait 2s for the next reading

  • The code starts by defining the pin number (MQ8pin) to which the MQ8 sensor is connected (in this case, A0).
  • In the setup function, the code sets pin 13 as an output pin to control the LED. It also initializes the serial communication at a baud rate of 9600 and prints a warming-up message to the serial monitor. The delay of 20 seconds allows the MQ8 sensor to warm up and stabilize.
  • Inside the loop function, the code reads the analog value from the MQ8pin and stores it in the sensorValue variable.
  • The sensor value is then printed to the serial monitor.
  • The code checks if the sensor value is greater than 400. If it is, it turns on the LED by setting pin 13 to HIGH. Otherwise, it turns off the LED by setting pin 13 to LOW.
  • The code adds a delay of 2 seconds before the next reading to ensure a reasonable interval between sensor readings.


Technical Details:

  • Target Gas: Hydrogen (H2)
  • Detectable Concentration: 100-10,000 ppm (Carbon Monoxide, CO)
  • Operating Voltage: 5V
  • Vc Circuit Voltage: 5V ± 0.1 AC or DC
  • VH Heating Voltage: 5V ± 0.1 AC or DC
  • PL Load Resistance: 10KΩ
  • RH Heater Resistance: 31 ± 5% at room temperature
  • PH Heating Consumption: Less than 800mW
  • Environment Conditions:
    • Operating Temperature (Tao): -10°C to 50°C
    • Storage Temperature (Tas): -20°C to 70°C
    • Relative Humidity (RH): Less than 95% RH
    • Oxygen Concentration (O2): 21% (standard condition); oxygen concentration can affect sensitivity, with a minimum value of over 2%
  • Sensitivity Characteristic:
    • Sensing Resistance (Rs): 10KΩ - 60KΩ at 1000ppm H2
  • Standard Detecting Condition:
    • Temperature: 20°C ± 2°C
    • Vc Circuit Voltage: 5V ± 0.1
    • Humidity: 65% ± 5%
    • VH Heating Voltage: 5V ± 0.1
    • Preheat Time: Over 24 hours
  • Detecting Concentration Scope: 100-10,000 ppm
  • Product Dimensions: 32mm (L) x 20mm (W) x 22mm (H)



Datasheet of the MQ8



While the MQ-8 sensor module is specifically designed for hydrogen gas detection, the MQ-2 and MQ-6 sensor modules have broader applications, as they can detect multiple gases, including hydrogen. The MQ-2 sensor module has a wider range of target gases, including LPG, propane, methane, alcohol, and H2. On the other hand, the MQ-6 sensor module focuses on detecting flammable gases such as LPG, butane, propane, methane, alcohol, and H2. Each sensor module has its specific sensitivity to the gases it is designed to detect, ensuring accurate and reliable measurements for their respective target gases the following is a detailed comparison between the MQ-8, MQ-2, and MQ-6 sensor modules in terms of the gases they detect and their sensitivity:

MQ-8 Sensor Module:

  • Target Gas: Hydrogen (H2)
  • Sensitivity: The MQ-8 sensor module is highly sensitive to hydrogen gas in the air. It can accurately detect H2 concentrations ranging from 100 to 1000 ppm.

MQ-2 Sensor Module:

  • Target Gases: The MQ-2 sensor module is designed to detect multiple gases, including:

    • LPG (Liquefied Petroleum Gas)
    • Propane
    • Methane
    • Alcohol
    • Hydrogen (H2)
  • Sensitivity: The MQ-2 sensor module exhibits good sensitivity to the above-mentioned gases, allowing for their detection in the surrounding environment. However, the sensitivity to specific gases may vary.

MQ-6 Sensor Module:

  • Target Gases: The MQ-6 sensor module is primarily used for the detection of flammable gases, including:

    • LPG (Liquefied Petroleum Gas)
    • Butane
    • Propane
    • Methane
    • Alcohol
    • Hydrogen (H2)
  • Sensitivity: The MQ-6 sensor module demonstrates high sensitivity to the mentioned flammable gases. It is designed to reliably detect and measure their concentrations in the air.