LPG Sensor modules are available now at low cost and we can use it in the Kitchen as a Gas leakage Alarm. The Module has a MQ6 Gas sensor, an Op-Amp as comparator and a preset for adjusting the sensitivity. All we need is a load resistor at the output to connect with the alarm circuit. Module is very sensitive to LPG (Liquefied Petroleum Gas) which contains Propane and Butane. The MQ6 sensor detects the gas concentration between 200 to 10,000 ppm.
The module works off 5 volts DC and has two outputs. The analogue output ( A) can be used to drive a buzzer through a driver transistor. The Digital output ( D) can be used for Micro controller based circuits.
How to Test?
Connect the Module with the Buzzer driver circuit as shown in Fig.1. Adjust the Preset in the module just to turn off the output LED. Then light a Cigarette lighter and keeping its knob pressed, puff off the fire. You can smell the gas. Show it near the Gas sensor and adjust VR1 (Load resistor) till the buzzer beeps. Pla
ce the circuit on the wall 1 foot above the Gas cylinder. Use a 9 volt battery to avoid electric wiring.