The MQ-6 Liquefied Isobutane Propane Sensor Module is a low-cost, highly sensitive semiconductor gas detection board designed for monitoring liquefied petroleum gas (LPG), isobutane, propane, and butane in domestic, industrial, and portable gas detection applications. Built around the MQ-6 sensor with a tin dioxide (SnO₂) sensing layer, this module offers high sensitivity to LPG-family gases while maintaining good resistance to interference from alcohol, cooking fumes, and smoke . It is an ideal solution for household gas leak alarms, industrial combustible gas detectors, and portable gas detection instruments.
At the heart of the module is the MQ-6 sensor element, whose conductivity increases as the concentration of target gases rises. In clean air, the sensor exhibits low conductivity; when exposed to LPG, isobutane, or propane, its resistance drops, producing a measurable change in output . The module provides two independent outputs: an analog output (AO) that varies continuously with gas concentration for trend monitoring, and a digital output (DO) that switches when the concentration exceeds a user-adjustable threshold set by the onboard potentiometer . This dual-output design makes it suitable for both quantitative trend analysis and simple threshold-based alarm triggering.
The module operates from 5V DC with a typical current consumption of approximately 150mA . It is compatible with Arduino, ESP32, and other 5V microcontrollers; Raspberry Pi users require an external ADC. The board features a compact 32 × 20 × 22mm form factor and an onboard LED indicator that provides visual feedback for power and digital output status .
Important Note: The MQ-6 requires a significant preheat time for stable operation. The sensor should be powered on for not less than 48 hours in clean air before initial calibration . After each power-up, allow at least 20 seconds to 2 minutes for the heater to stabilize. The sensor is not a calibrated industrial-grade detector and should not be used as a sole life-safety device. Its sensitivity degrades over time, and periodic replacement is recommended for critical applications. The sensor surface becomes hot during operation — avoid touching it. The module is not waterproof and should be kept dry. Avoid exposure to organic silicon vapors, high concentrations of corrosive gases, or alkali metal salts, which can permanently damage the sensing element .
Whether you are building a home gas leak alarm, an industrial LPG detector, or an educational sensor project, the MQ-6 module provides a reliable, affordable solution for liquefied gas and propane detection.
Features
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MQ-6 SnO₂ semiconductor sensor — High sensitivity to LPG, isobutane, propane, and butane
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Good anti-interference — Resistant to alcohol, cooking fumes, and smoke interference
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Dual output — Analog (AO) for concentration trends, Digital (DO) for threshold alarms
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Adjustable threshold — Onboard potentiometer sets the digital output trigger point
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Wide detection range — 300–10,000 ppm for propane, butane, and LPG
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5V operation — Compatible with Arduino, ESP32, and other 5V microcontrollers
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LED indicators — Power and digital output status feedback
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Compact form factor — 32 × 20mm PCB for easy integration
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Fast response and recovery — Quick detection of gas concentration changes
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Wide application range — Household gas alarms, industrial detectors, portable instruments
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Sensor Model | MQ-6 (SnO₂ semiconductor) |
| 2 | Target Gases | LPG, Isobutane, Propane, Butane |
| 3 | Detection Range | 300 – 10,000 ppm (Propane/Butane/LPG) |
| 4 | Operating Voltage | 5V DC |
| 5 | Heater Voltage | 5.0V ± 0.2V AC/DC |
| 6 | Heater Power Consumption | ≤ 900mW |
| 7 | Output Type | Analog (AO) + Digital (DO/TTL) |
| 8 | Preheat Time | Not less than 48 hours |


























