MQ3 module

Description

The sensor determines the concentration of alcohol in the air, the result can be obtained measuring the voltage on the analog output. The system is powered with the voltage from 2.5 V to 5 V. It has a digital and analog output, making it compatible with mostof the commissioning modules including Raspberry Pi and Arduino.

The digital output D0

With the help of placed on the reverse side of the board, potentiometer, set is the threshold, exceeding of which, causes the output D0 changing from a high to a low status. The pin D0 can be linked directly with a microcontroller or commissioning set, including Arduino, or for example, a module with a buzzer, which will signal a too low or too high level of alcohol in the air.

Analog output A0

The sensor has an analog output A0, which must be connected to the pin of the converter A/D (analog input in Arduino). This will allow you to measure the proportional voltage signal and more accurately determine the level of alcohol.

Operating principle:
MQ-3 gas sensor applies SnO2 which has a lower conductivity in the clear air as a gas-sensing material. In an atmosphere where there may be alcohol gas, the conductivity of the gas sensor raises along with the concentration of the alcohol gas increases.