The MQ-3 Alcohol Detector Sensor Module is a 32mm x 20mm x 22mm SnO2 semiconductor sensor specifically sensitive to ethanol and alcohol vapor, operating at 5V DC with 150mA current consumption and a 200kΩ onboard load resistance. The mq3 sensor is widely known as the breathalyzer sensor — its strong selective response to ethanol vapor (the alcohol found in alcoholic beverages) makes it the go-to choice for DIY breath alcohol testing projects, distinct from the combustible-gas, CO, and air-quality-focused MQ-5/6/7/8/9/135 sensors.
The mq3 gas sensor module provides both AO (analog output, 0.1-0.3V baseline) and DO (digital output, switching between 0.1V and 5V at a threshold) outputs simultaneously — the gas sensor module’s onboard 200kΩ load resistance forms part of the voltage divider that produces the AO reading, and this value matters if calculating expected voltage ranges for different alcohol concentrations. The alcohol detection sensor analog reading increases as ethanol vapor concentration near the sensor increases — in breathalyzer builds, the sensor is typically positioned close to where the user exhales.
MQ3 also responds to benzene, hexane, and LPG vapour at high concentrations, so it is not suitable for precise gas identification. Students building breathalyser projects and alcohol detection systems use it. To start, connect, and read the analog pin after a 60-second warm-up. StemVolt provides sensors with trusted quality, ensuring reliable performance and easy usability.
Related Products:
- Checkout The MQ-4 CNG Methane Natural Gas Sensor Module
Features:
- Selective ethanol/alcohol vapor sensing for breathalyzer-style projects
- Both AO analog and DO digital outputs available simultaneously
- 200kΩ onboard load resistance forms voltage divider for AO
- 5V DC at 150mA with standard MQ-series heater warm-up
- Compact 32x20x22mm fits handheld breath-test enclosure designs
Technical specifications:
Applications:
- MQ-3 Sensor used for Arduino DIY breathalyzer demo build
- College project uses mq3 sensor for alcohol detection science demo
- STEM kit uses mq3 gas sensor module for breath sensor learning
- Safety device uses gas sensor module for India alcohol presence alert
- Lab demo uses alcohol detection sensor for ethanol vapor sensing test
Package includes:
- 1 x MQ-3 Alcohol Detector Sensor Module
Sukhdev Jakhar –
Bubble wrap packing ensured safe delivery, while multiple payment options and after sale support made the purchase experience convenient and hassle-free
Ranjeet Chahal –
Alcohol detector sensor module provides reliable alcohol vapor detection and is ideal for science exhibitions, educational experiments, and gas sensing projects
Jaswant Tanwar –
Suitable for ATL lab activities, robotics projects, and sensor-based learning applications requiring alcohol detection capabilities.
Mahendra Godara –
Same day dispatch
Bhanwar Bhati –
Original product received
Gajendra Charan –
Impressed with quality