This is an Arduino Alcohol sensor. It uses a MQ3 probe which can be used in a Breathalyser. It has a high sensitivity to alcohol and less sensitivity to Benzine. The sensitivity is able to be adjusted by the potentiometer. The output is proportional to the density of gas. You can use analog reading to read the data from this sensor. To ease the difficulty of using this sensor, a Gravity Interface is adapted to allow plug&play. The Arduino IO expansion shield is the best match for this senor connecting to your Arduino microcontrollers. Features * Standard assembling structure (Times-of-5mm Center distance between four 3mm(0.12") mounting holes) * Easily recognitive interfaces of sensors ("A" for analog and "D" for digital) * Icons to simplely illustrate sensor function * High quality connector & potentiometer * Immersion gold surface Connection Example - I/O Expansion Shield V7 Specifications * Power supply: 5V * Interface type: Analog * High sensitivity to alcohol and small sensitivity to Benzine * Fast response and High sensitivity * Stable and long life * Simple drive circuit * Size: 36.4 x 26.6mm Resources * Product Wiki * Schematic * MQ-3 datasheet Package Contents * 1x Arduino Alcohol Sensor (MQ3) * 1x Analog Cable https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2023-03-06 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2023-12-27 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2024-09-19 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2024-11-29 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2024-11-30 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2025-02-14 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2025-04-11 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2025-08-05 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2025-11-28 https://elecena.pl/product/22714857/gravity-analog-alcohol-sensor-mq3 2025-11-29