In this tutorial, you will learn how to calibrate and use MQ9 gas sensor with an Arduino board.
What You Will Learn
What Is A Gas Sensor And How Does It Work?
MQ Gas Sensor Series
|Sensor Name||Detectable gas|
|MQ2||Methane , Butane , LPG , Smoke|
|MQ3||Alcohol , Methanol , Smoke|
|MQ9||Carbon monoxide , Flammable gases|
|MQ216||Natural gas , Coal gas|
|MQ4||Methane , CNG gas|
The MQ9 sensor is sensitive to carbon monoxide and flammable gases. It can detect the detect carbon monoxide density from 10ppm to 1000ppm and flammable gases density from 100ppm to 10000ppm. MQ9 has an internal heater which starts warming up if a 5V voltage is applied.
The internal resistance of this sensor changes as the density of the detectable gases changes. This value can be read by a simple circuit. MQ9 sensor modules in the market have already implemented the necessary circuit and you do not need any extra item.
Interfacing MQ9 Gas Sensor and Arduino
In order to get correct and accurate data, you need to take the following actions first:
- MQ9 sensor needs 24-48 hours of preheating time. Connect the power supply and leave for the required time until it gets ready.
- You need to calibrate the sensor (We have explained this in the following section)
How to Calibrate MQ9 Gas Sensor?
/* MQ9 Calibration modified on 19 Feb 2019 by Saeed Hosseini
/* MQ9 modified on 19 Feb 2019 by Saeed Hosseini
- Find the gas concentration in PPM with the help of the above table.
- Create an intelligent CO leakage notifier.