The MQ-6 is a semiconductor device for detecting the levels of propane and butane in the air. Since liquefied petroleum gas (LPG) is composed of these two gases, then the MQ-6 can be used as a LPG sensor. Introduction For this tutorial, I will be using the MQ-6 breakout board: [the_ad id="3059″] It ensures that heater element inside the sensor will not cause an explosion, as we are sensing flammable gases. It also provides protection for the sensor and filters out suspended particles so that only gaseous elements are able to pass inside the chamber. The mesh is bound to rest of the body via a copper plated clamping ring. Structure and configuration of MQ-8 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of sensitive components. MQ-6 gas sensor is used in the SEN 1327 module. The output signal from SEN 1327 gas sensor module is used to drive a 555 timer-based astable multivibrator circuit. Here 555 timer works as a tone generator, the frequency of tone can be altered by varying the preset VR1. Circuit Diagram of Gas Leakage Sensor Alarm Circuit It is one of the straightforward gas sensors so it works almost the same way with other gas sensors. It costs $6.90.Typically, it is used as part of the breathalyzers or breath testers for the detection of ethanol in the human breath. 2. Datasheet Here is a datasheet, only 2 pages. A gas sensor is a device that senses the atmosphere's presence or concentration of gases. The sensor creates a corresponding potential difference depending on the concentration of the gas by adjusting the resistance of the material within the sensor, which can be determined as the output voltage. The type and concentration of the gas can be The gas sensitive material used in the MQ-2 gas sensor is SnO2, a low electrically conductive material in clean air. When there is combustible gas in the surrounding air, the electrical conductivity of the sensor will increase with the higher intensity of the combustible gas. Working Principle. After wiring VCC and GND, the Power LED of the Working on this smoke detector alarm circuit is easy. In this article, we used the transistor operating properties to work with this circuit as a smoke detector. BC547 NPN transistor will turn on whenever it gets at least 0.70v at its base terminal. MQ6 gas sensor is also sensible to the LPG, alcohol, methane, etc. Related posts: Full-Wave About this project. This gas sensor uses a MQ-2 gas sensor to indicate if there is gas in the area. so the sensor has a threshold value (the threshold value is around the amount of smoke in there is a fire) in that if it goes above it starts alerting people in the vicinity. The alert just shows a red led and starts beeping. MQ137 Ammonia Gas Sensor Profile Sensitive material of MQ137 gas sensor is SnO 2, which with lower conductivity in clean air. When NH 3 gas exists, the sensor's conductivity gets higher along with the gas concentration rising. Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit. A Gas sensor's working principle is serve to measure the concentration of gases in the environment. There are many different types depending on what yo