MQ-3 Alcohol Sensor Module with LM393 Comparator

Alcohol sensor module, e.g. in exhaled air (breathalyzer) with a comparator. It has digital and analog outputs, which makes it compatible with most commissioning modules, including Arduino.

The sensor detects alcohol concentration in the air, the result can be obtained from the voltage measurement on the analog output.
The sensor module has a digital and analog output, which makes it compatible with most commissioning modules, including Raspberry Pi and Arduino.
Due to the use of the LM393 comparator, the module has a binary output (D0) which is low or high.
The module has a potentiometer to adjust the sensitivity and LED diodes indicating power supply and sensor status.
The module has an analog and digital output

Specification:
- Power supply: 5V
- Current consumption max 150mA
- Measuring range: 0.04 mg / L - 4 mg / L
- Converter: 0.1 mg / L = 0.21 ‰.
- Working temperature: -20 to 50 ° C
- Connector: goldpin header, 2.54mm pitch
- Dimensions: 35 x 22 mm


MQ-3 Module in action:

- Digital output D0.
With the help of the potentiometer placed on the back of the board, the threshold is set, after which the output D0 goes from high to low. The D0 pin can be connected directly to a microcontroller or commissioning kit, including Arduino, or, for example, with a buzzer module, which will signal too low or high levels of undesirable gases in the air

- Analog output A0
The sensor also has an A0 analog output, which should be connected to the A/C converter (analog input in Arduino). This will allow you to more accurately determine the concentration by measuring the proportional voltage signal.

Pinout:
- digital (binary D0),
- analog (A0)
- Vcc power supply (+ 3.3-5V)
- GND (0V ground)