MQ-3 Gas Sensor Module – Alcohol (Ethanol) - EXEMQ3

Alcohol sensor module MQ-3 is used to measure the concentration of ethanol in the air. It is successfully used at an ethanol concentration of 0.05mg/l to 10mg/l. It is powered by a voltage of 2.5V to 5V, with a current consumption of about 200mA. The board features a circuit providing two output interfaces – analog and digital. The analog output generates a voltage signal corresponding to the detected ethanol concentration. The digital output works on a trigger principle – when a certain threshold is crossed, a high output level (logic 1) is obtained. The trigger threshold corresponds to a certain ethanol concentration and is adjusted via a potentiometer. For optimal sensor performance, the manufacturer recommends preliminary calibration. This is done by exposing the sensor to the ambient environment (air). The measured value should be equal to 0.4mg/l (approximately 200ppm).

Wiring diagram (when using an Arduino-type microcontroller):

Additional information:

• Getting Started
• Building a breath alcohol analyzer device