MQ-3

General Description:

MQ-3 Alcohol Detector Module which can sense the presence of Alcohol in the air. It provides an analog output corresponding to the concentration of the gas in the air and an easy-to-use digital output. The onboard potentiometer can be used to set the maximum gas concentration beyond which the digital output gets triggered. Just power the module with 5V, set the threshold, and you can start getting the gas concentration of the air around the sensor. An onboard LED signals the presence of any gas. Perfect sensing alcohol concentration on your breath just like a common breathalyser.

Working Principle:

The MQ-3 gas sensor utilizes a semiconductor material, such as tin dioxide, as its sensing element. When powered, the built-in heater element raises the semiconductor's temperature, rendering it catalytically active. Upon exposure to alcohol vapor, the surface conductivity of the semiconductor changes, resulting in a measurable alteration in electrical resistance. This change in resistance is then translated into a voltage signal for alcohol concentration detection. 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 rises along with the concentration of the alcohol gas increases.

Specifications:

1. Operating voltage: 2.5 V to 5 V.
2. Boost converter to boost the sensor sensitivity.
3. It has the signal output indicating LED.
4. This sensor is sensitive to alcohol, and ethanol.
5. Adjustable sensitivity.
6. Has both Analog and Digital outputs.

Applications:

1. Automotive safety systems
2. Breathalyzer devices
3. Industrial safety monitoring
4. Home automation
5. Drunk driving incidents