MQ4 Methane Gas Sensor : Pin Configuration & Its Applications

• Gas leaks cause air pollution and are hazardous, they may also lead to fire outbreaks.
• Gas sensors notify us whenever there is a gas leak by releasing an output signal similar to the amount of gas leak.

• The Mq4 gas sensor is the most used methane gas sensor, as it is less sensitive to other gases or alcohol.
• It is a semiconductor gas sensor that detects the presence of methane (CNG) gas at concentrations from 300 ppm to 10,000 ppm, it is a range suitable for detecting gas leaks.
• The sensor’s analog voltage interface requires only one analog input pin from the microcontroller.
• The example is- this sensor could detect if someone left a gas stove on but not lit.

Pin Configuration

• AO (Analog output Pin)- an output is released in an analog form whose value depends on the efficiency of sound. (0 to 5 V).
• DO(Digital output Pin)- a digital output whose logic high and logic low are determined with the use of a potentiometer.
• VCC (Power supply)- voltage 5v is given.
• GND(ground)- connected to ground.

• A, B, and H are another group of pins.
• A: Anyone is used as the output pin and the other as GND.
• B: both are connected to supply.
• H: One connected to the ground and the other to the supply.
• Pins A and B can be interchanged.

Features of MQ4 Methane Gas Sensor

• Detection Gas- Natural Gas/Methane
• Concentration- 300-10000ppm
• Supply Voltage- <24V
• Heater Voltage- 5.0V ± 0.2V
• Load Resistance- Adjustable
• Heater Resistance- 31Ω ± 3Ω
• Heater Consumption- <900mW

Applications of MQ4 Methane Gas Sensor

• Gas leak detection at home or in industries.
• Gas sensors are required near large garbage bins.