MQ131 Ozone Gas Sensor Module


MQ131 Ozone gas sensor module belongs to the MQ gas sensor family infamous for their use in the early detection and warning of toxic concentrations of harmful gases in a closeby vicinity. MQ131 sensor possesses lower conductivity in clean air and higher conductivity when the ozone concentration rises. The core sensing element in MQ131 sensors is SnO2 which allows for quick detection of the harmful concentration of Ozone gas. MQ131 sensor also possesses strong sensitivity to strong oxides such as Cl₂, NO₂ &, etc. It responds oppositely to organic interference gases. The sensing range is 10 – 1000ppm. The sensor is easily interfaceable with almost every MCU such as Arduino Uno, ESP32, NodeMCU, etc.

MQ131 gas sensor is widely used in domestic ozone concentration alarms, industrial ozone concentration alarms, and portable ozone concentration detectors. The module also features ESD protection and overvoltage protection capabilities.

MQ131 Ozone Gas Sensor Module-2

MQ131 Gas Sensor Key Features

  • High Sensitivity to Ozone and heavy oxide gases.
  • The operating Voltage is +5V
  • Can be used to detect LPG or Butane gas
  • Analog output voltage: 0V to 5V
  • Digital Output Voltage: 0V or 5V (TTL Logic)
  • ESD protection
  • Overvoltage protection
  • Preheat duration 20 seconds
  • Simple drive circuit
  • Fast response
  • Stable and Long life

MQ131 Gas Sensor Pinout

MQ131 Ozone 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
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.


  • Sensor Type: Semiconductor
  • Standard Encapsulation: Bakelite (Black Bakelite)
  • Detection Gas: Ozone
  • Concentration: 10-1000ppm
  • Loop Voltage Vc: ≤24V DC
  • Heater Voltage VH: 5.0V±0.2V AC or DC
  • Load Resistance: Adjustable
  • Sensitivity S: Rs(in air)/Rs(in 50ppm O3)≥3
  • Slope (α): (R50ppm/R10ppm O3)
  • Tem. Humidity: 20℃±2℃;65%±5%RH
  • Preheat time: Over Forty-Eight hours
  • Sensing Resistance: Rs 50KΩ-500KΩ(in 50ppm O3)


  • Used in gas leakage detecting equipment for Research labs and industry. They are suitable for detecting O3 and high concentrations of heavy oxide gases.
  • Industrial Ozone gas detector
  • Portable Ozone concentration overload Detector


You can download the datasheet for the MQ131 Ozone (O3) 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