Description
MQ-5 LPG and Natural Gas Sensor Module
This module uses an MQ-5 tin-dioxide semiconductor sensor that responds to several combustible gases, especially LPG/propane and methane, which is a major component of natural gas. Response varies with gas composition and environmental conditions, so the sensor is not selective enough to identify a gas mixture or provide a dependable calibrated concentration without a carefully designed and calibrated system.
🔧 Sensor reference specifications
- Sensor type: semiconductor (SnO₂)
- Manufacturer-stated targets: LPG, methane and propane
- Manufacturer-stated test range: 300–10,000 ppm for CH₄/C₃H₈ under specified test conditions
- Heater supply: 5.0 V nominal
- Heater power: up to approximately 950 mW in the cited specification
- Sensitivity adjustment: present on some module versions; verify the actual board
The range above is a sensor test specification, not a promise that this breakout gives accurate ppm readings. The French listing mentions “coal gas”; gas mixtures vary, and that phrase should not be treated as a guaranteed target or a selective identification capability.
⚙️ Warm-up and calibration
The sensing element is heated. The manufacturer specifies a preheat period of at least 48 hours for its standard test conditions. Allow readings to stabilize and calibrate the actual sensor and circuit before using thresholds. Temperature, humidity, airflow, sensor age and other vapours can change the response.
🔌 Typical breakout connections
Check the labels on the supplied board; common versions provide VCC, GND, analog output (AO) and a comparator-based digital output (DO). The heater normally requires a stable 5 V supply and can consume close to 1 W. Use an appropriately rated supply and never power the heater from a microcontroller GPIO. Check AO/DO voltage before connecting to a 3.3 V-only input; use suitable level shifting or protection where needed.
💡 Suitable prototype uses
- Demonstrating combustible-gas sensor response in a supervised lab
- Microcontroller analog-input and threshold-comparator experiments
- Non-critical trend monitoring prototypes
Safety notice: this hobby module is not a certified LPG or natural-gas alarm, industrial monitor or life-safety device. Do not rely on it to detect a leak or protect people or property, and do not replace approved alarms with it. Use certified equipment and follow local safety requirements for real gas detection. Never release flammable gas intentionally for testing.
