MQ9 Gas Sensor

The MQ9 Gas Sensor is a semiconductor gas sensor designed for detecting carbon monoxide (CO) and combustible gases such as methane (CH₄). Its sensing element changes resistance according to the concentration of gas present, allowing the change to be measured through a suitable circuit. It is commonly used in gas leakage alarms, safety monitoring systems and portable gas detection equipment.

Technical specifications:

• Sensor Type: Semiconductor Gas Sensor
• Target Gases: Carbon Monoxide (CO) and Methane (CH₄)
• CO Detection Range: 10–500 ppm
• Methane Detection Range: 300–10,000 ppm
• Heater Voltage: 5.0V ±0.1V at high temperature / 1.5V ±0.1V at low temperature
• Heater Resistance: Approximately 29Ω ±3Ω at room temperature
• Heater Consumption: ≤900mW
• Load Resistance: Adjustable

Features:

• Good sensitivity to carbon monoxide and methane
• Wide gas concentration detection range
• Simple interfacing circuit
• Durable metal mesh protective housing
• Suitable for continuous gas-monitoring applications
• Compact through-hole design for PCB mounting
• Cost-effective solution for gas detection systems

Applications:

• Carbon monoxide leakage alarms
• Domestic gas safety systems
• Industrial gas monitoring
• Portable gas detectors
• Combustible gas detection systems
• Safety and alarm projects
• Microcontroller-based gas monitoring systems