MQ-4 gas sensor sensitive material used in clean air conductivity is lower tin dioxide (SnO2). When the sensor is present in the environment in which the combustible gas, the sensor’s conductivity increases with the concentration of combustible gases in air increases. Using a simple circuit can be converted to the change in conductivity of the gas concentration with the corresponding output signal. MQ-4 methane gas sensor for high sensitivity, propane, butane and has a good sensitivity.

The sensor can detect a variety of flammable gases, especially natural gas, is a low-cost sensors for a variety of applications Using high-quality dual-panel design, with power indicator and TTL signal output instructions.
The switching signal having a DO (ITL) output and analog output AO. TTL output valid signal is low. ( Low-level signal when the output light can be directly connected to the microcontroller or relay module )Analog output voltage with the higher concentration of higher voltage

• There are four screw holes for easy positioning
• Has a long life and reliable stability
• Rapid response and recovery characteristic
• Input voltage : DC5V Power consumption ( current): 150mA
• DO output: TTL digital 0 and 1 ( 0.1 and 5V)
• AO output :0.1-0.3 V (relative to pollution), the maximum concentration of a voltage of about 4V
• Special note: After the sensor is powered,needs to warm up around 20S, measured data was stable,heat sensor is a normal phenomenon,because the internal heating wire,if hot is not normal.
• Wiring:
  • VCC: positive power supply (5V)
  • GND: power supply is negative
  • DO: TTL switching signal output
  • AO: analog signal output