Specification:

Features:

• Multi-Gas Detection:
  Capable of detecting Carbon Monoxide (CO) and combustible gases such as Methane (CH₄) and Liquefied Petroleum Gas (LPG).

• High Sensitivity:
  Excellent sensitivity to CO and flammable gases, with fast response time and recovery.

• Dual Heater Modes:
  Operates in two-cycle heating modes to differentiate between CO and combustible gases for more accurate readings.

• Analog & Digital Output:
  Provides analog voltage output for gas concentration and digital output (via comparator and threshold setting) for easy integration.

• Adjustable Sensitivity:
  Onboard potentiometer to calibrate and adjust the digital output threshold according to your requirement.

• Long Life & Stability:
  Long-lasting sensing element with reliable performance and minimal drift over time.

• Easy to Interface:
  Compatible with Arduino, Raspberry Pi, ESP32, and other microcontrollers using standard I/O pins.

• Working Voltage:
  Typically operates on 5V DC.

• PCB Module Version:
  Usually mounted on a breakout board with signal pins, LED indicators, and mounting holes for convenience.

Description:

This is MQ-9 Carbon Monoxide, Methane, and LPG Gas Sensor Module can be used to sense Carbon Monoxide and Methane Gas. The sensitive material of the MQ-9 gas sensor is SnO2, which with lower conductivity in clean air.
It makes detection by the method of cycle high and low temperature, and detect CO when the low temperature (heated by 1.5V). The sensor’s conductivity is higher along with the gas concentration rising. The MQ9 Gas Sensor Module conductivity is higher along with the gas concentration rising. When temperature rises (heated by 5.0V), it detects Methane, Propane, combustible gas, etc. and cleans the other gases as it absorbed under low temperature. MQ-9 usually applied in domestic gas leakage detector, industrial gas detector, portable gas detector, etc.
When the high temperature (heated by 5.0V), it detects Methane, Propane, etc. combustible gas and cleans the other gases adsorbed under low temperature.

Read our blog MQ sensor where we explained what is a gas sensor, what is 1ppm equal to, MQ sensor list of different series and their features.