gas leakage alaram full report

The gas leakage circuit uses the SEN-1327 gas sensor module from RhydoLABZ. Its output goes high when the gas level reaches or exceeds certain point. A preset in the module is used to set the threshold. Interfacing with the sensor module is done through a 4-pin SIP header.

Pin details of the gas sensor module are shown in Fig. 2. An MQ-6 gas sensor is used in the gas sensor module. The sensor can also be used to detect combustible gases, especially methane.

Whenever there is LPG concentration of 1000 ppm (parts per million) in the area, the OUT pin of the sensor module goes high. This signal drives timer IC 555, which is wired as an astable multivibrator. The multivibrator basically works as a tone generator.

Output pin 3 of IC 555 is connected to LED1 and speaker-driver transistor SL100 through current-limiting resistors R5 and R4, respectively. LED1 glows and the alarm sounds to alert the user of gas leakage. The pitch of the tone can be changed by varying preset VR1. Use a suitable heat-sink for transistor SL100.

LPG gas is supplied in pressurised steel cylinders. As this gas is heavier than air, when it leaks from a cylinder it flows along floor and tends to settle in low spots such as a basement. This can cause fire or suffocation if not dealt with.

Here is a circuit that detects the leakage of LPG gas and alerts the user through audio-visual indications.

Fig. 1 shows the circuit of the gas leakage alarm. The circuit operates off a 9V PP3 battery. Zener diode ZD1 is used to convert 9V into 5V DC to drive the gas sensor module.

The SEN-1327 gas sensor module from RhydoLABZ is used in this circuit. Its output goes high when the gas level reaches or exceeds certain point. A preset in the module is used to set the threshold. Interfacing with the sensor module is done through a 4-pin SIP header.


Whenever there is LPG concentration of 1000 ppm (parts per million) in the area, the OUT pin of the sensor module goes high. This signal drives timer IC 555, which is wired as an astable multivibrator. The multivibrator basically works as a tone generator.

Output pin 3 of IC 555 is connected to LED1 and speaker-driver transistor SL100 through current-limiting resistors R5 and R4, respectively. LED1 glows and the alarm sounds to alert the user of gas leakage. The pitch of the tone can be changed by varying preset VR1. Use a suitable heat-sink for transistor SL100.

Working of gas leakage alarm
Zener diode Z1 is used to regulate the Vcc to 5V DC to drive the gas sensor module. See Voltage regulator using zener diode.
The sen-1327 gas sensor module from Rhydolabz is used in this circuit. Its output goes high when the gas level exceeds definite point.
A preset employed in the module is used to set the threshold or reference level. Interfacing with the SEN 1327 sensor module is done through a 4 pin SIP header.
A MQ-6 gas sensor is used in the module. As per its datasheet, it has high sensitivity to propane, butane, isobutene, LPG and natural gas.
Each time there is LPG concentration of 1000 ppm (parts per million) in the area, the OUTPUT pin of the sensor module goes high.
High voltage at the 4th pin (Reset pin) enables timer IC 555, which is wired as an astable multivibrator. The multivibrator essentially works as a tone originator.
Without the high voltage at 4th pin (Reset pin) the IC remain in the Reset state.
Output pin 3 of IC 555 is connected to LED1 and speaker driver transistor SL100. LED1 glows and the alarm sounds to aware the user of gas leakage.
The pitch of the tone can be changed by varying preset VR1.
Provide a suitable heat sink for transistor SL100.

This system helps you to upgrade your safety standards, comply statutory requirements on environmental commitments and most important and basic function being prevent accidents and protect life and property from disaster. In the past, it has been a conventional practice to employ combustion apparatus such as a furnace, heater, stove or LPG kit in cars, which utilizes a combustible vapor or gas to produce heat energy when properly ignited. In the use of combustible apparatus in which a combustible gas such as natural or liquid propane gas is burned in heating boilers,
domestic water heaters, ovens, stoves and the like, the apparatus or appliance is generally of an automatic recycling type. That is to say, the equipment is generally in operation for short periods of time after which is shut down for a short period of time. The equipment has intermediate operation and the appliance is generally started and stopped at the signal of an automatic controller, such as a thermostat, which may be
actuated by temperature, pressure, or the like. The LPG Kit installed is many times installed inside the car creating possibilities of large accidents. This type of appliance/Kits is normally unattended by any operating personnel, since it is automatic in operation and, therefore, one hazard encountered in the use of such an appliance is the possibility that during a standby period or a period in which it is not in operation, a gas leak may occur thereby resulting in a large accumulation of combustible gas which can produce an explosion if the detection is not quickly noticed. Although some sophisticated detector means have been provided, it is contemplated that the indicator means should be simple and economical so that the
entire system may be readily incorporated into mobile trailers, campers, boats and other vehicles or living quarters having appliances dependent upon storage of pressurized gas.