MQ8 Hydrogen Gas Sensor Module


MQ8 is a Metal oxide semiconductor (MOS) type sensor from the MQ gas sensors family. MQ8 hydrogen gas sensor includes a detecting element like aluminum-oxide (Al₂O₃) based ceramic material that is covered with SnO2 (tin dioxide) and arranged in a stainless-steel mesh. The module is highly sensitive to Hydrogen gas and can be used to detect any leaks or presence of Hydrogen gas in the air. MQ8 gas sensor can detect hydrogen gas concentrations anywhere from 100-10000ppm (parts per million).

This sensor has a high sensitivity to hydrogen gas and a fast trigger response time. The sensor’s output is analog resistance corresponding to the concentration of hydrogen gas in the vicinity. The drive circuit is very simple; all that is required to do is to power up the heater coil with 5V, add a load resistance, and connect the output to an ADC. MQ8 gas sensor is low cost and is suitable for all kinds of different applications for detecting poisonous concentrations of hydrogen (H2) gas.

MQ8 Hydrogen Gas Sensor Module

MQ8 Gas Sensor Key Features

  • Detects H2 Gas concentration in air
  • Resistant to LPG, smoke, alcohol
  • Heater power consumption: < 800mW
  • Can detect H2 gas in the concentration range of 100-10000ppm
  • Analog output is continuous
  • Compact size
  • Less cost
  • Dual signal output
  • Quick response
  • Reliable and long service life

MQ8 Gas Sensor Pinout

MQ8 Hydrogen Gas Sensor Module Pinout
Pin NamePin No.Description
VCC1This pin powers the module, typically the operating voltage is +5V
GND2Used to connect the module to the system ground
DO3You can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer
AO4This pin outputs 0-5V analog voltage based on the intensity of the gas.


  • Operating Voltage: 5V DC
  • Size: 11 x 33 x 20 mm.
  • Range: 100-10000 ppm.
  • Characteristic gas: 100 ppm CO.
  • Sensitive resistance: 2 to 20 10 Kilo ohm/10 Kilo ohm at 100ppm CO.
  • Sensitivity: ≥ 3%.
  • Return time: ≤ 30 s.
  • Heating resistance: ± 31ohm 3ohm.
  • Heating current: ≤ 180 mA.
  • Reaction time: ≤ 1 s.
  • Heating voltage: 5.0V ± 2V / 1.5 ± 1V.
  • Heating power: approx. 350 mW.
  • Ambient temperature: -20 ° C to + 50 ° C.
  • Humidity: ≤ 95% RH.


  • Used in gas leakage detecting equipment for homes and industry.
  • Industrial Hydrogen gas detector
  • Portable H2 gas detectors


You can download the datasheet for MQ8 Hydrogen Gas Sensor Module by clicking the link given below:

See Also: SIM900A Dual Band GSM/GPRS Module | DS3231 Precision I2C Real-Time Clock Module | MT8870D Integrated ISO2-CMOS DTMF Receiver Module