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"Experiments" with the MQ-3 Alcohol Sensor



The MQ-3 Alcohol Sensor is one of a series of easy to use gas sensors that can be easily connected to an Arduino.  This sensor can be used to measure the blood alcohol content in a person by measuring the amount of alcohol is on their breath.

After work one Friday afternoon I set up the following circuit and test software.  The setup was a lot easier than I thought.


The arduino test code

unsigned int val = 0;
unsigned char PIN = 0;
void setup() {
void loop() {
    val = analogRead(PIN);

The "Experiment"

  1. Take test measurement before drinking
  2. Drink 1 shot of alcohol
  3. Wait 10 minutes without drinking
  4. Record test measurement
  5. Repeat steps 2-4 

The data

I will add here the results of the test data:
  1. Data on the warm up period when the sensor first turns on (this is why I wait for 30 seconds in my LPG Gas Sensor code before taking measurements)
  2. Data regarding the alcohol recorded on the breath of two test subjects.

Wiring diagram and schematic