Description
A Gas detector is a device that detects the presence of gases in an area.
- Gas sensors spontaneously react to the gas present.
- These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected.
- Different types of gas sensor available in the market like
MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9. - Each type has unique characteristics to detect the gas.
- Sensitive material of Gas sensor is SnO2, which has lower conductivity in clean air.
- When the target flammable gas exists, the sensor’s conductivity gets higher along with the gas concentration rising.
- Gas sensor can detect different kinds of flammable gases, especially has high sensitivity to LPG (propane).
Application
- Domestic gas leakage alarm.
- Industrial flammable gas alarm.
- Portable gas detector.
Hardware Required

- Gas Sensor.
- Atmega16 MicroController.
Pin Diagram

- VCC: +5v.
- A0: Analog Output.
- GND: GND.
Circuit
