LPG (Liquefied Petroleum Gas) is widely used for cooking and heating. It mainly contains propane and butane, which are highly combustible. Leakage may occur due to faulty regulators, damaged pipes, or loose connections.
An LPG Gas Leak Detector continuously monitors air quality and alerts users when dangerous gas levels are detected.
Objectives :
- Detect LPG leakage quickly
- Provide early warning through an alarm
- Prevent fire accidents
Improve home and industrial safety
Main Components :
1. Gas Sensor
- MQ-6 Gas Sensor (best for LPG detection)
- Detects propane and butane gases
- Analog and digital output
- Detects propane and butane gases
2. Microcontroller
- Arduino Uno / ESP32
3. Output Devices
- Buzzer (Alarm)
- LED Indicator
- LCD Display (optional)
- GSM Module (optional for SMS alert)
4. Power Supply
- 5V DC supply
CIRCUIT DIAGRAM
Applications :
- Home kitchens
- Restaurants
- LPG storage units
- Gas pipelines
- Industrial plants
- Laboratories
Connection Description (Wiring Map – ESP32 Version) :
Component | Arduino Pin | Description |
MQ-6 VCC | 5V | Power supply |
MQ-6 GND | GND | Ground |
MQ-6 A0 | A0 | Analog output |
Buzzer | D8 | Alarm output |
LED | D9 | Visual indicator |
GSM TX | D2 | Serial communication |
GSM RX | D3 | Serial communication |
Common Ground | GND | Shared ground |
Working Principle :
- Gas Detection
- MQ-6 sensor detects LPG concentration in the air.
- Sensor resistance changes with gas concentration.
- MQ-6 sensor detects LPG concentration in the air.
- Signal Processing
- Analog value sent to Arduino.
- Microcontroller compares the value with the threshold.
- Analog value sent to Arduino.
- Alert Activation
- If gas level exceeds safe limit:
- Buzzer turns ON
- LED glows
- SMS alert sent (optional)
- Buzzer turns ON
- If gas level exceeds safe limit:
- Continuous Monitoring
- System keeps monitoring the gas level in real time.
Testing the Hardware :
Step 1: Sensor Calibration
- Power the MQ-6 sensor for 2–5 minutes to stabilize.
Step 2: Gas Exposure Test
- Carefully release small LPG near the sensor.
- Observe an increase in sensor reading.
Step 3: Alarm Test
- Confirm buzzer and LED activate above threshold.
Step 4: GSM Test (Optional)
- Verify SMS is received when gas is detected.
Applications :
- Home kitchens
- Restaurants
- LPG storage units
- Gas pipelines
- Industrial plants
- Laboratories
Troubleshooting :
Problem | Possible Cause | Solution |
No sensor output | Wrong wiring | Check connections |
False alarms | Low threshold | Adjust sensitivity |
Buzzer not working | Pin error | Verify output pin |
No SMS | GSM network issue | Check the SIM card |
Sensor unstable | Not warmed up | Wait for calibration |
( The LPG Gas Leak Detector is a safety system designed to detect leakage of Liquefied Petroleum Gas (LPG) in homes, laboratories, and industries. LPG is highly flammable and can cause fires or explosions if leaked. This system uses a gas sensor to detect LPG concentration in the air and triggers an alarm, buzzer, or SMS alert when the gas level exceeds a safe limit. The project provides an effective and low-cost solution to prevent accidents and ensure safety. )