Gas Detecting Alarm system with Arduino Uno

PROJECT DEMONSTRATION When a gas is detected above some permissible limit immediately the buzzer produces a tone according to the code written! NOTE: By changing the value of the resistor across which output is measured the sensitivity of the gas sensor can be varied. SENSITIVITY:It is the minimum change needed in the external parameter to observe a change in the output voltage of the sensor. Here, external parameter is the amount of gas particles. So if we increase then the resistance value for a small change in the amount of gas in the atmosphere a significant change in the output voltage can be observed.

WHAT IS A GAS SENSOR? The gas sensor is a chemical sensor that detects the amount of gas in the atmosphere. There are many gas sensors available, according to our requirement we can pick one. A list of various gas sensors and the gases they can detect is given below. Sensor Name Gas to measure MQ-2 Methane, Butane, LPG, Smoke MQ-3 Alcohol, Ethanol, Smoke MQ-4 Methane, CNG Gas MQ-5 Natural gas, LPG MQ-6 LPG, butane MQ-7 Carbon Monoxide and many more.

MQ-2 gas sensor is a metal oxide direct chemical sensor(a direct sensor chemical/gas sensor is the one in which an electrical property like resistance, voltage, current, etc is changed when the sensor comes in contact with a gas. It can detect methane, butane, LPG gases but it can’t differentiate between the gases but it can just tell us the quantity of the above gases present in the atmosphere.

PIEZO BUZZER Piezo buzzer is a device that can create any tone of the desired frequency. It is used as an alarm and creates high-intensity sounds if needed. It is made up of piezoelectric material(piezoelectric material is the one which produces mechanical stress when electricity is applied to it and vice versa).The ceramic element expands and contracts when a signal(generally a square wave) is applied to it thus it makes the outer plate to vibrate and leading to generation of a tone or sound of desired frequency.

ARDUINO UNO The Arduino Uno is a microcontroller board based on the ATmega328. It has 20 digital input/output pins (of which 6 can be used as PWM outputs and 6 can be used as analog inputs), a 16 MHz resonator, a USB connection, a power jack, an in-circuit system programming (ICSP) header, and a reset button.

APPLICATIONS: ⦁ This application can be used in factories to detect the leakage of hazardous chemicals. ⦁ It can be used in houses to detect the leakage of gases like LPG if ignored might even lead to death. ⦁ Main purpose of project is to ensure safety of the society from hazardous chemicals.