Ethanol Alcohol Gas Sensor Module – MQ-3

Description

The MQ-3 alcohol gas sensor detects the concentration of alcohol gas in the air and relays its reading as an analog voltage. Its high sensitivity, fast response, and stable, long life make it ideal for use in a breathalyzer or a car alcohol alarm.  It uses tin oxide which is highly sensitive to alcohol.  The MQ-3 will sense concentrations between 0.05 mg/L to 10 mg/L (the legal limit of breath alcohol concentration in most US states is 0.38 mg/L). The sensor can operate at temperatures from -10 to 50°C and consumes less than 150 mA at 5 V.

$latex \Large \%BAC = \frac{(\textrm{Concentration, mg/L})}{\textrm{1000 mg/g} \times \textrm{10 dL/L}} \times \frac{(\textrm{2100 mg/L Blood})}{(\textrm{1 mg/L Breath})}  \times \frac{\textrm{1 }\%\textrm{BAC}}{\textrm{1 g/dL}}&s=1$

or

$latex \%BAC = \frac{ 21 \times (\textrm{Concentration, mg/L})}{100}&s=1$

Technical Specs

• Supply Voltage: 5 V
• Supply Current: 150 mA
• Output Type: Analog
• Gases Detected: Alcohol (-OH)
• Concentration Range: 0.05 – 10 mg/L (0.01 – 2.1 %BAC)

Resources

• MQ-3 Datasheet