Introduction

A Gas Leakage Detector is an electronic system designed to detect the presence of harmful gases like LPG, Methane, or Propane in the environment. When gas is detected above a threshold concentration, the system triggers an alarm to prevent accidents and ensure safety.

This project is highly relevant for home safety, industries, and laboratories.

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Objective of the Project

• To detect gas leakage in real-time.
• To provide an alert when dangerous gas levels are present.
• To interface a gas sensor with Arduino.
• To improve safety and prevent accidents.

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Working Principle

The Gas Leakage Detector works on the principle of gas sensing using a semiconductor sensor (MQ-2 / MQ-5).

Step-by-Step Working

1. The gas sensor continuously detects the concentration of gases.
2. When the gas concentration exceeds a safe threshold, the sensor output changes.
3. Arduino reads the sensor signal.
4. The system triggers a buzzer or LED alert.

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Components Required

• Arduino Uno
• Gas Sensor (MQ-2 / MQ-5)
• Buzzer
• LED
• 220Ω Resistor (for LED)
• Jumper Wires
• Breadboard / PCB
• 5V Power Supply

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Circuit Diagram

Connections

MQ-2 / MQ-5 Gas Sensor:
VCC  -> 5V
GND  -> GND
AO   -> A0 (Analog output to Arduino)

Buzzer:
Positive -> D8
Negative -> GND

LED:
Positive -> D9 via 220Ω resistor
Negative -> GND

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Arduino Code for Gas Leakage Detector

int gasSensor = A0;
int buzzer = 8;
int led = 9;

int threshold = 300; // Adjust according to sensor calibration

void setup() {
  pinMode(buzzer, OUTPUT);
  pinMode(led, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int gasLevel = analogRead(gasSensor);
  Serial.print("Gas Level: ");
  Serial.println(gasLevel);

  if (gasLevel > threshold) {
    digitalWrite(buzzer, HIGH);
    digitalWrite(led, HIGH);
    Serial.println("Gas Leak Detected!");
  } else {
    digitalWrite(buzzer, LOW);
    digitalWrite(led, LOW);
  }

  delay(1000);
}

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Code Explanation

• MQ sensor reads the gas concentration.
• Analog value is sent to Arduino.
• If the value exceeds threshold, buzzer and LED turn ON.
• Alerts user of potential gas leakage.

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Advantages

• Prevents accidents caused by gas leaks
• Real-time monitoring
• Easy to implement
• Low cost

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Applications

• Home LPG leakage detection
• Industrial safety systems
• Laboratories
• Smart home automation

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Future Enhancements

• GSM module integration to send SMS alerts
• IoT monitoring with mobile notifications
• Automatic gas valve shutoff
• Integration with voice alerts

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Conclusion

The Gas Leakage Detector is a vital electronics project for safety and automation. It helps students learn about sensor interfacing, analog-to-digital conversion, and microcontroller-based alert systems. Its practical applications make it a highly useful and impactful project.