The MQ-5 Flammable Gas Sensor is a metal-oxide semiconductor gas sensor designed to detect combustible gases—such as LPG, natural gas, town gas, methane, propane, and butane—across a concentration range of 300 to 10,000 ppm.
Key Specifications & Features
* Sensitive Material: Tin Dioxide (SnO₂), which increases in electrical conductivity as the concentration of flammable gas rises.
* Operating Voltage: Typically 5V DC (heater and module logic).
* Interference Resistance: Offers low cross-sensitivity to alcohol, cooking fumes, and cigarette smoke compared to general-purpose sensors.
* Outputs:
* Analog Output (AOUT): Provides a continuous voltage signal (0–5V) that scales with gas concentration.
* Digital Output (DOUT): Provides a TTL high/low switch signal governed by an onboard threshold-adjusting potentiometer.
Typical Applications
* Domestic gas leakage detectors and safety alarms.
* Industrial flammable gas monitoring devices.
* DIY microcontroller and IoT projects (compatible with Arduino, ESP32, and Raspberry Pi via an ADC).
(Note: These metal-oxide sensors require a preheat period of roughly 1–3 minutes upon power-up to yield stable readings, and provide a relative trend of gas concentration rather than a certified laboratory measurement.)