What Is the MQ-2? Gas and Smoke Sensor: Specs and Uses
The MQ-2 is a gas sensor that detects flammable gases and smoke (LPG, propane, methane, hydrogen, smoke). Its module gives an analog (AO) and a threshold digital (DO) output. It has an internal heater (5 V); accurate reading needs preheating (a few min, ideally ~24-48 h burn-in) and calibration for ppm. The family has MQ-3/MQ-7/MQ-135 for different gases.
The MQ-2 is a gas sensor that detects flammable gases and smoke (LPG, propane, methane, hydrogen, smoke). With its module's analog (AO) and digital (DO) outputs it is very common in hobby/safety projects. For the concept, see what is a sensor.
What is the MQ-2 used for?
Gas-leak/smoke alarms, air-quality monitoring and safety projects. The analog output varies with gas concentration; the digital output triggers when the threshold set by the module's pot is crossed.
Watch out: heater, preheat and calibration
The MQ-2 has an internal heater, so it heats up and draws power (5 V). For accurate measurement it needs preheating (a few minutes on first use, ideally a ~24-48 hour "burn-in"). For an exact value in ppm, calibration for the environment is required; without calibration it suits only relative change/an alarm threshold.
Specifications
| Parameter | Value |
|---|---|
| Detects | LPG, propane, methane, H2, smoke |
| Output | Analog (AO) + digital (DO, threshold) |
| Supply | 5 V (with heater) |
The MQ family
Different members for different gases: MQ-3 (alcohol), MQ-7 (carbon monoxide), MQ-135 (air quality/NH3/CO2 etc.). Choose the right member for the target gas.
Equivalents
- MQ-5 / MQ-6: LPG/natural-gas focused.
- MQ-135: general air quality.
- CCS811 / MH-Z19: digital (I2C/UART) air/CO2 sensors.
Find it in our catalog
Use the MQ-2 search.