MQ-9 Gas Sensor Module for Carbon Monoxide, Methane and LPG

MQ9 Gas Sensor is a Metal Oxide Semiconductor (MOS) type Gas Sensor of MQ Gas Sensors family involving MQ 2, MQ 4, MQ 3, MQ 135, etc. It is mainly used to detect gases like Carbon Monoxide, Methane, and Propane, etc. This MQ9 Smoke Sensor contains a sensing element, mainly aluminum-oxide based ceramic, coated with Tin dioxide (SnO₂), enclosed in a stainless steel mesh. Whenever gas comes into contact with the sensing element, the resistivity of the element changes. The change is then measured to get the concentration of the gases present. It has a small heating element present which is needed to preheat the sensor to get it in the working window. It can detect LPG, Propene, Hydrogen, Carbon Monoxide, and Methane Gas concentrations. It finds uses in detecting gas leakage in pipelines, Alarm application in case of a gas leak at home as CO is a very harmful gas and can kill a person if present over 300PPM.

MQ9 Gas Sensor Specifications

• Operating Voltage is +5V
• Can be used to Measure or detect LPG, Propane, CO, and Methane
• Analog output voltage: 0V to 5V
• Digital Output Voltage: 0V or 5V
• Long life and Low Cost
• Heater consumption ≤350mW
• The Sensitivity of Digital Output pin can be varied using the potentiometer

Product Description

To use the Sensor Module, you have to power the device with 5V supply and the Power LED will start to glow. To power it, you can use external supply or connect +5V and GND pin of Arduino. You should give it some preheating time before start reading the output. While measuring the gas present, the Output LED will glow in a specific concentration of the gas. You can change it by using the potentiometer. Else you can also use the Analog Output to see how your program reacts to different concentrations of gases present.

Package Contents

1×MQ-9 CO Gas Sensor Module

Additional Resources

Arduino Interfacing with MQ 9 Sensor