MQ-3 Gas sensor

The MQ3 Gas Sensor module is useful for gas leakage detection (in home and industry). It is suitable for detecting Alcohol, Benzine, CH4, Hexane, LPG, CO. Due to its high sensitivity and fast response time, measurements can be taken as soon as possible. The sensitivity can be adjusted by using the potentiometer on the module.

MQ-3

My sensor was wired up as follows

Code

Same as the MQ2 sensor

[codesyntax lang=”cpp”]

void setup() 
{
  Serial.begin(9600);
}
 
void loop() 
{
  float sensorVoltage; 
  float sensorValue;
 
  sensorValue = analogRead(A0);
  sensorVoltage = sensorValue/1024*5.0;
 
  Serial.print("sensor voltage = ");
  Serial.print(sensorVoltage);
  Serial.println(" V");
  delay(1000);
}

[/codesyntax]

Results

I saw the following results in the serial monitor

sensor voltage = 1.83 V
sensor voltage = 1.78 V
sensor voltage = 1.74 V
sensor voltage = 1.70 V
sensor voltage = 1.66 V
sensor voltage = 1.63 V
sensor voltage = 1.59 V
sensor voltage = 1.56 V

Links

Mq-3 Gas sensor specs
MQ-3 Alcohol Ethanol Sensor Breath Gas Ethanol Detection