How to get percentage value of different gases using the MQ135 gas sensor

Question

How can I get percentage values of co2, nh3, alcohol, smoke and benzene from a MQ135 gas sensor  . I've been using raspberry pi 3 and arduino for the project. thanks.

Answer 1

I don't think the MQ135 can do what you are asking. It basically shows a value representing air quality and not individual pollutants. Use the datasheet if you want to understand what it reports if calibrated properly.

If you're working with a naked sensor (no breakout board or printed circuit board), then you can try this:

Read the datasheet to make sense of the given wiring diagram. 

Then code your sketch as follows:

int value;
int sensorPin = A0;
int sensorValue = 0;

void setup()
{
  Serial.begin(9600);      // sets the serial port to 9600
}

void loop()
{
  sensorvalue = analogRead(sensorPin);   
  Serial.println(value, DEC);  // print decimal value
  delay(100);                  // wait at least 100 milliseconds 
}

Comments

Thanks for sharing this article.

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Thanks for sharing this nice information

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If MQ135 cannot do this then which sensor should I go for?