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Gas Leak Sensor

At a glance

Category: Public Safety & Emergency Systems In your kit: ×1 (MQ-series gas sensor) Status: 🚧 Full tutorial coming soon

What it is

A gas sensor that detects combustible and some toxic gases in the air — typically LPG, natural gas, smoke, and alcohol vapour. It gives an analog output: the reading rises when gas concentration rises.

Gas Leak Sensor

This sensor gets warm

MQ-series gas sensors have a small internal heater. The metal case will get warm to the touch during operation — this is normal. It also means the sensor needs about 20–60 seconds to warm up after power-on before readings are accurate.

Safety first

Never deliberately leak real cooking gas or LPG to test this sensor. For testing, use a safe demonstration: bring an open but not lit cigarette lighter close to the sensor (gas without flame), or use rubbing alcohol on a cotton swab — both will trigger the sensor. Do this outdoors or in a well-ventilated room under adult supervision.

What you'll build with it

  • Kitchen gas-leak alarm (pairs with Active Buzzer + RGB LED showing green/yellow/red)
  • Air-quality monitor for the Connected City dashboard project
  • Safety shutoff for a laboratory simulation (pairs with the Relay)

Before this page is filled in

See the DHT11 tutorial for the pattern every sensor page follows once complete.