MQ136 Hydrogen Sulfide Gas Sensing Module


The MQ136 Hydrogen sulfide gas detection module belongs to the MQ gas sensor family infamous for its use in the early detection and warning of toxic concentrations of harmful gases in a closeby vicinity. The core sensing material of the MQ136 gas sensor is SnO2, offering a lower conductivity under nominal conditions (clean air) and a higher conductivity ratio when the target hydrogen sulfide gas (H2S) reaches a dangerous concentration in the nearby vicinity.

MQ136 H2S gas sensor is easily interfaceable with almost every MCU such as Arduino Uno, ESP32, NodeMCU, etc, allowing the obtained data to communicate over various different mediums and IoT devices.

MQ136 Hydrogen Sulfide Gas Sensing Module

MQ136 Gas Sensor Key Features

  • Dual signal output (analog output and TTL level output)
  • The TTL output effective signal is low.
  • Analog output 0 ~ 5V voltage, the higher the concentration the higher the voltage.
  • Size: 32mm X22mm X27mm (length X width X height)
  • The main chip: LM393, ZYMQ-136 gas sensors
  • Good sensitivity to hydrogen sulfide, liquefied gas, natural gas, city gas, and smoke.
  • with long service life and reliable stability
  • fast response recovery characteristics
  • ESD protection
  • Overvoltage protection

MQ136 Gas Sensor Pinout

MQ136 Hydrogen Sulfide Gas-Sensor-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
Digital Out (DO)3You can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer
Analog Out (AO)4This pin outputs 0-5V analog voltage based on the intensity of the gas.


  • Model No: MQ136
  • Sensor Type: Semiconductor
  • Standard Encapsulation: Bakelite (Black Bakelite)
  • Detection Gas: Hydrogen Sulfide
  • Concentration: 1-200ppm
  • Loop Voltage Vc: ≤24V DC
  • Heater Voltage VH: 5.0V±0.2V AC or DC
  • Load Resistance: Adjustable
  • Heater Consumption: ≤900mW
  • Heater Resistance: 31Ω±3Ω (Room Temp.)
  • Sensitivity S: Rs(in air)/Rs(in 50ppm H2S)≥3
  • Slope (α): (R50ppm/R10ppm H2S)
  • Temp. Humidity: 20℃±2℃;65%±5%RH
  • Preheat time: Over Forty-Eight hours
  • Sensing Resistance: Rs 2KΩ-20KΩ(in 50ppm H2S)


  • Detect or measure harmful concentrations of sulfide Gases
  • Air quality monitoring systems
  • Hydrogen sulfide Gas leak alarm
  • Industrial SO2 leakage detector
  • Portable SO2 detector
  • Safety standard maintenance system


You can download the datasheet for MQ136 Hydrogen Sulfide Gas Sensing Module by clicking the link given below:

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