MQ3 Module

The MQ-3 sensor module is based on the MQ3 Alcohol gas sensor as an alcohol gas sensing element. MQ-3sensor is ideal for detection or measuring of Alcohol concentration at a range from 0.05 mg/L to 10 mg/L.  It offers very good sensitivity and fast response to alcohol and good resistance to disturbances due to smoke, vapour and gasoline make it ideal for use in gas leakage types of equipment. The module comes with basic components integrated allowing the sensor to function properly. And interfaced easily to any controller as the user prefers. Hence no external components are required, we need to just plug in Vcc & ground pins and you are ready to go.

MQ3 module consists of both digital and analogue outputs. This module not only provides a binary indication of the presence of combustible gases but also an analogue representation of their concentration in air. When gas is detected using the digital output, the indicator LED D0 turns ON. As a result, the digital pin will go from logic high to logic low 0V. The presence of onboard LM393 comparator IC in the MQ3 module also eliminates the need for an external microcontroller. Simply power up the module and set the sensitivity of the digital pin using the potentiometer. So when the module detects the gas the digital pin will go low. MQ3 Alcohol sensor module can be easily interfaced to any Microcontroller, Arduino or even Raspberry Pi.

While using the analogue pin to measure PPM, the TTL drove (0-5V) analogue pins read values using a microcontroller that calculates the resistance value. By using the external load resistance the resistance variation is converted into a suitable voltage variation. This will be directly proportional to the concentration of the gas to which the sensor detects.