Methane is a part of every household. It is a need of humans. For survival, it is necessary as we cook our daily food items using this natural gas. But, the leakage of this gas is harmful. Many accidents happen because of this. Therefore, it is important to use a device that detects the leakage when it happens. And, the MQ4 sensor is especially for this detection. Below you would read deeply about that sensor.
An Overview about MQ4 Sensor
Working Principle
The sensor acts by detecting the methane concentration in the air. The sensor includes the analog pin that generates an analog signal proportional to the volume of Methane or CNG in the air. Hence, one can estimate the analog output of a sensor with a microcontroller having an analog-to-digital converter.
Internal Structure of MQ4 sensor
The structure and configuration of the MQ4 gas sensor comprise a micro-ceramic tube of AL2O3, a sensitive layer of Tin Dioxide, measuring electrode, and heater which are fixed into a crust formed by plastic and stainless steel net. The heater provides basic work conditions for the practice of sensitive components. The sensor has six pins. From which four of them are used to fetch signals, while the other two are there for providing heating current.
Features and Specifications of MQ4 Sensor
Features
- High sensitivity to CH4, Natural gas.
- Small sensitivity to alcohol, smoke.
- Fast response
- Stable and long life
- Simple drive circuit
- The sensor is a simple and stable circuit with a TTL DO pin.
- The device sensitivity may vary due to oxygen concentration.
- It is very sensitive to methane making it quite useful for detecting systems
- A small compact sensor for easy assembly in DIY projects.
Specifications
- Operating Voltage: 5V±0.1
- Heating voltage: 5V±0.1
- Load Resistance: 2K
- Sensing Resistance Range: 10 – 60K
- CH4 Sensing Range: 300 – 10000 ppm
- Sensor Heat Consumption: ≤ 950 mW
- Relative Humidity: >95% RH
- Standard Oxygen concentration: 21%
- Output Analog Voltage: 2.5 – 4 Volts (5000 ppm CH4)
- Preheating Time: Over 48 Hours
Pinouts of MQ4 Sensor
| Pin Name | Description |
| Vcc | Power Pin requires an operating voltage of 5V. |
| GND | Ground pin. |
| DO | Digital out the pin, to get the digital output from the sensor, need to set the threshold value using Pot. |
| AO | Analog out the pin. It based the output of this pin on the intensity of the methane gas. |
Applications
Environmental Monitoring Systems
The environmental air monitoring system can provide a suitable monitoring method that uses an MQ-4 sensor. This is a lightweight, customer-friendly, and low-cost air monitoring device that can measure Methane gas we can use this anywhere
Methane Testing/Detecting Devices
Through this system, we can immediately collect information on methane, and we can also display other gases which can be processed by any microcontroller, and the results on the OLED display
Gas Leakage Detecting Equipments
The goal of detecting a gas leak is to prevent the worst potential causes of the gas leak, using the above type of MQ sensor. The choice of the MQ-4 sensor is because of the nature of MQ-4 which is suitable for detecting natural gas.
