The Engineering Projects

MQ-8 Hydrogen Gas Sensor: Datasheet, Pinout & Working

Hey fellow! Welcome to the next article on the MQ series of sensors, and today our focus is on the MQ-8 which is used to sense the presence of hydrogen gas. We know that hydrogen is a colorless, odorless, and tasteless gas that humans can not sense easily. It is not toxic like carbon monoxide and other such examples but still, the excess presence of this gas can be life-threatening because it is highly flammable. The air is a mixture of different gases and hydrogen gas when combined with some specific gases, can be harmful to life. In the presence of a bare flame or other ignition material, hydrogen can start the ignition, and here, the duty of sensors like MQ-8 starts. We’ll examine the basic information about this sensor in detail.

In this article, we’ll start reading about the basic introduction to the MQ-7 hydrogen gas sensor. We’ll see the basic data sheet, specifications, features, and core information about this product. After that, we’ll move on to this work in detail and understand its structure to analyze its output. We’ll end this chapter with the physical dimensions and the applications of this sensor in different domains of life. There are many things to learn here so let’s move towards the first topic:

MQ-8 Hydrogen Gas Sensor Introduction

The MQ-8 is a specialized sensor mainly designed to sense the surplus amount of hydrogen gas that can be harmful to people with sensitive lungs because excess inhalation of hydrogen can displace the oxygen atoms in the lungs. Moreover, it may be inflammable in the factories or industries using the particular material.

For some materials, the hydrogen gas can be the cause of brittleness and even cracks therefore, is a harmful gas for materials like storage tanks and pipelines. In such areas, the sensors like MQ-8 are used to detect the presence of any hydrogen gas leakage. The structure is designed in such a way that as soon as the surplus amount of hydrogen is sensed in the environment, it sends the signal through the analog and digital pins to the output devices for indication.

Here are the basic parts of the MQ-8 hydrogen sensor:

MQ-8 Hydrogen Gas Sensor Sensing Element

The heart of this sensor is the sensing element that lies on the base of a circuit that continuously heats it. This element is made of ceramic material that has a layer of tin dioxide (SnO2) on it. This layer is responsible for absorbing the high concentration of hydrogen gas in the surroundings as a result, the sensor can indicate its presence. 

MQ-8 Hydrogen Gas Sensor Heater

A heater circuit is present in the core of this sensor which is a heater coil that is wrapped around the sensing element and continuously heat it. This circuit is always on and this constant heating is crucial for the accuracy of the sensor performance. 

MQ-8 Hydrogen Gas Sensor Electrodes

Two electrodes are connected to the sensing element that is responsible for working according to changes in the circuit resistance. This resistance depends on the ion formation reaction on the sensitive element. 

MQ-8 Hydrogen Gas Sensor Filter

A stainless steel mesh network is present on the whole circuit that consists of two layers. These layers are responsible for the following tasks:

1. Protection of the internal element from the outward unwanted particles. It simply allows the gases to pass through it to filter the articles. 

2. Helps the internal structure to retain its position. 

Moreover, it has pins, voltage regulators, filtering capacitors, and pre-heat resistors that support the smooth performance of the MQ-8 hydrogen gas filter.

MQ-8 Hydrogen Gas Sensor Datasheet

Let us discuss some important parts of the datasheet that will help you understand the product details. We’ll are making a start with its features:

MQ-8 Hydrogen Gas Features

• It is a sensitive detector and its range is between 100 to 10,000 PPM where the PP means the parts per million. 

• It can sense the small leakage of hydrogen gas and, therefore, is considered a reliable sensor. 

• The structure is designed in such a way that it detects the hydrogen gas accurately even in the presence of other gases such as methane, ethanol, and carbon monoxide. As a result, the sensor does not provide the false alarms. 

• This sensor shows a fast response time that ranges between 30 seconds to 100 seconds after it is powered on. 

• It has a simple and small circuit that does not consume a lot of energy. Moreover, the easy circuit makes it less costly.

• Another advantage of a simple circuit is its long life. Moreover, it is a lightweight device. 

MQ-8 Hydrogen Gas Sensor Specifications

Here is a table of the specifications for the MQ-8 hydrogen gas sensor:

MQ-8 Hydrogen Gas Sensor Internal Structure

The internal structure of this sensor is simple as discussed before in the previous section. Here is the diagram that will explain the internal circuit and its basic labeling:

This diagram will be understood by using the detail of each label as mentioned below:

1.  Gas Sensing Layer (SnO2):

• SnO2 material used for gas sensing.

2.  Electrode (Au):

• Electrode made of gold (Au).

3.  Electrode Line (Pt):

• Electrode line composed of platinum (Pt).

4.  Heater Coil (Ni-Cr Alloy):

• Heater coil material: Nickel-chromium alloy (Ni-Cr).

5.  Tubular Ceramic (Al2O3):

• Tubular ceramic material: Aluminum Oxide (Al2O3).

6.  Anti-explosion Network:

• Stainless steel gauze (SUS316 100-mesh) is used as an anti-explosion network.

7.  Clamp Ring (Copper Plating Ni):

• Clamp ring made of copper with nickel plating.

8.  Resin Base (Bakelite):

• Resin base material: Bakelite.

9.  Tube Pin (Copper Plating Ni):

• Tube pin made of copper with nickel plating.

If you want to know more about the datasheet then you can visit the link given below:

MQ-8 Hydrogen Gas Sensor Pinout Configuration

As with all members of the MQ series, the MQ-8 hydrogen gas sensor has four pins and in some models, an additional pin is also present. Here is the table that shows the pin number, its name, and a brief description:

MQ-8 Hydrogen Gas Sensor Packages

For the convenience of the user, manufacturers present different types of packages for the MQ sensors. Here is the table that explains the SMD and DIP package of the MQ-8 hydrogen gas sensor:

Where to Buy MQ-8 Hydrogen Gas Sensor?

there are multiple options to buy such products online but the most trusted ones are listed below:

• eBay

• AliExpress

• Amazon

MQ-8 Hydrogen Gas Sensor Working Principle

If you've followed the details about the sensor's structure in the previous section, understanding how the MQ-8 hydrogen sensor works should be straightforward. Here are the steps that show the working principle in this regard:

• As soon as the sensor is powered on, the heating circuit starts its duty. In 20 to 100 seconds, it starts heating the sensing element. 

• The heating process stimulates the tin oxide to absorb the oxygen gas from the surroundings. This created a depletion region consisting of hydrogen ions around the tubular-shaped tin oxide.

• Soon, the depletion region is strong enough to enhance the resistance of the circuit. At this point, the MQ-8 hydrogen sensor is ready to sense the pure hydrogen gas in the environment. 

• In the case when there is a leakage of the hydrogen gas, the sensing element starts reacting with it. 

• If there is a notable amount of hydrogen in the environment, the depletion region around the sensing element starts resting with it. As a result, the resistance of the circuit starts decreasing. 

• The values of the electrical current passing through the circuit increase and eventually, the analogue values are sent to the output device through the analogue pin. 

• By the same token, the digital pin is stimulated when a particular analogue value is crossed. 

• These signals are then sent to the output device. Usually, the projects are made using any microcontroller or other such devices.  

MQ-8 Hydrogen Gas Sensor Physical Dimensions

The physical dimensions of such products vary from model to model. I‘ve created a general table that shows the dimensions of the MQ-8 hydrogen gas sensor mentioned here:

MQ-8 Hydrogen Gas Sensor Applications

Hydrogen gas is not toxic and it is less commonly used as compared to the other gases therefore, it is not widely used in household applications but it is used in the areas where large amount of hydrogen is used. Here is the list of examples of some applications:

• Industrial hydrogen gas monitoring

• Hydrogen gas leakage detection

• Fuel cell applications

• Hydrogen-powered vehicle safety

• Chemical processing environments

• Laboratory gas detection

• Hydrogen storage facilities

• Aerospace industry applications

• Hydrogen fuel production and storage

• Energy-related processes

Today, we learned a lot about the MQ-8 hydrogen gas sensor. We initiated the discussion through the introduction of this sensor where we discussed its basic parts. Following that, we moved into the datasheet, uncovering a trove of information encompassing features, specifications, and the sensor's internal architecture. Progressing further, we unveiled the intricacies of its working principle, concluding our exploration with a glimpse into the diverse applications harnessing the potential of this sensor. If you crave more knowledge, stick around for our forthcoming insights.

MQ-7 Carbon Monoxide Sensor: Datasheet, Pinout & Working

Hello peeps! I hope you are having a good day. We all know carbon monoxide is a dangerous and harmful gas that can even be fatal. It is a colorless and odorless gas so it is difficult to sense its presence therefore, different types of sensors and indicators are required to make the places safe especially those where there is a chance for carbon monoxide gas production as a byproduct. Here, one of the most promising detectors is the MQ-7 carbon monoxide sensor which instantly detects and indicates the presence so the users may save their lives. This is the most popular choice for this purpose because of its low cost, high performance, and instant response. 

This article will commence by introducing the MQ-7 carbon monoxide sensor. Subsequently, we will delve into essential details from its datasheet, exploring its structure, pinout configuration, and performance-related graphs. Additionally, we will examine alternatives and package details, providing a comprehensive understanding. A detailed exploration of the working principle will follow. Towards the conclusion, notable examples highlighting the significant role of this sensor will be discussed. Let's embark on the exploration of the initial topic:

MQ-7 Carbon Monoxide Gas Sensor Introduction

The sensitive material of the MQ-7 carbon monoxide gas sensor is tin dioxide (SnO2). This is a reactive material to carbon monoxide and the basic working of this sensor depends on the heating process of this sensing element. Carbon monoxide (CO) is not usually present in fresh air therefore, the sensor does not provide any signal until it senses any leakage or danger.

This sensor consists of the following parts:

MQ-7 Carbon Monoxide Gas Sensor’s Gas Sensitive Layer

Just like other MQ sensors, this one also has a sensitive element made of ceramic that has a layer outside it. This layer consists of tin dioxide (SnO2) and has the feature of absorbing the target gas. In the case of MQ7, the tin dioxide absorbs the carbon monoxide and indicates its presence as soon as it comes in contact.

MQ-7 Carbon Monoxide Gas Sensor’s Gas Electrodes

The MQ-7 has electrodes that facilitate electrical contact with the sensitive material. Usually, it is made with the gold for the best performance. These allow the measurement of the electrical resistance.

MQ-7 Carbon Monoxide Gas Sensor’s Heater Coil

There is a coil in the heart of this sensor. This is made of alloy like Ni-Cr and provides heat to the sensitive layer to enhance its reaction and sensitivity.

MQ-7 Carbon Monoxide Gas Sensor’s Tubular Ceramics

The censor has a tubular structure of ceramic material such as alumina (Al2O3) and it provides support and strength to other components so that they may be at their place.

MQ-7 Carbon Monoxide Gas Sensor’s Anti-explosion Network

There is a network of double stainless steel mesh that performs two functions:

1. It allows the gases to pass through it and retains the presence of any unwanted particles outside the network.
2. It protects the internal structure because that is very reactive and delicate therefore, with the help of this network, all the internal structure remains in its place.

MQ-7 Carbon Monoxide Gas Sensor’s Resin Base

To create the whole system of the gas sensor, there is a firm base made with bakelite or other materials that provide the strength and the pin structure that ensure the working of the whole sensor.

Moreover, there are tube pins and clamp rings that provide extra strength to the circuit of the MQ-7 monoxide gas sensor. 

MQ-7 Carbon Monoxide Sensor Datasheet

Before using any electrical component, it is important to understand the technical specifications. Here are some points to know before using the MQ-7 carbon monoxide sensor:

MQ-7 Carbon Monoxide Sensor Features

• This sensor has an analog pin that shows the presence of carbon monoxide through the analog values

• The digital pin is responsible for showing the presence or absence of the gas through a single value. 

• It has a simple structure therefore, it is a less power-consuming component. 

• It has a long life and is considered ideal to use in circuit-like IoT projects.

• It is continuously in power so whenever it senses carbon monoxide in its surroundings, it shows a rapid response. 

• The typical detection range of this sensor is 10 ppm to 1000 ppm but it may vary depending on the model. 

MQ-7 Carbon Monoxide Sensor Specification

MQ-7 Carbon Monoxide Sensor Pinout Configuration

Just like structure and other features, the pinout configuration of the MQ-7 carbon monoxide sensor has four pins and a simple structure. Here is the table that shows the pin number, names, and a brief description:

The details of each pin will be clear when we study the working of this sensor in the communing section.

MQ-7 Carbon Monoxide Sensor Packages

For the convenience of the users, the MQ-7 carbon monoxide is available in different packages. Here is the detail of the most common packages:

MQ-7 Carbon Monoxide Sensor Through-Hole Package (DIP)

• This is the most common package that usually has four pins for connection to a PCB through the soldering process.

• It's readily available for use and the advantage is, that it has easy integration into existing circuits.

• The negative point is, that it requires manual soldering and has a larger footprint compared to other packages.

MQ-7 Carbon Monoxide Sensor Surface Mount Package (SMD)

• This package is relatively smaller and is designed for surface mounting on PCBs.

• It offers easier integration into printed circuit boards and therefore is used by beginners as well. 

• The negative point is, that it requires specialised soldering equipment that is not always available for all the users and may be more sensitive to environmental factors.

MQ-7 Carbon Monoxide Sensor Module Package

• It includes the sensor itself along with additional components for better working such as the voltage regulators and filtering capacitors.

• It's easier to use as compared to the other options in the list and provides plug-and-play functionality.

• The negative point is, that it has a larger footprint and can be more expensive compared to basic packages.

MQ-7 Carbon Monoxide Sensor Alternatives

Some other fellows of the MQ family also can detect carbon monoxide to some extent but it is advisable to use the most sensitive and particular devices to detect such types of toxic gases. Here are noteworthy alternatives that can substitute for the MQ-7 carbon monoxide gas sensor:

• MQ-9 is another sensor from the MQ series and it can detect multiple gases including carbon monoxide and methane. 

• MiCS-5524 is the sensor that can detect gases like Carbon Monoxide, Methane, and LPG Gas Sensor. It's a small sensor and is used in multiple projects in different domains. 

• An important alternative for this sensor is the Figaro TGS Series that have multiple gas sensors for gas detection. 

• The SGX Sensortech MICS-5524 is another sensor that can detect carbon monoxide, methane, and LPG gas and shows high sensitivity towards multiple gases. 

Where to Buy MQ-7 Carbon Monoxide Sensor

Buying the electrical component is a big responsibility because every member of the circuit affects the overall accuracy. You must buy sensors like MQ-7 without facing technical issues:

• eBay

• AliExpress

• Amazon

MQ-7 Carbon Monoxide Sensor Working Principle

• The basic working principle of this sensor is similar to the other MQ series compoeents. In the heart of this sensor, the tin oxide (SnO2) is present in a tubular shape. The circuit of this sensor is designed in such a way that as soon as the circuit is powered on, the tin oxide is heated to stimulate its absorption process at a high rate. 

• Once the tin oxide is stimulated, it absorbs the oxygen from its surroundings and the ions are created at a high rate. As a result, a depletion region forms around the sensing element that enhances the electrical resistance. 

• Now, the electric current passing through the sensor is very small and this indicates that there is no toxic carbon monoxide present in the surroundings. 

• As soon as there is an amount of CO in the air and it reaches the sensor, the depletion region starts reacting with it and as a result, the smaller number of ions contributes to less resistance. 

• In the end, the low resistance results in the high electrical conductance that is indicated in the sensor. 

• The output on the analog pin is directly proportional to the amount of carbon monoxide present in the air. 

• MQ-7 has a potentiometer in it through which the threshold values are set. Once the analogue values reach the threshold value, the sensor shows the signal through the digital pin. A comparator is used in the module that is responsible for comparing the values on these pins. 

• These pins are connected to the output devices which may be any buzzer, screen, or anything else based on the project. 

MQ-7 Carbon Monoxide Sensor Physical Dimensions

Before using MQ-7 in the circuit, the physical dimensions will help you to understand its size and other specifications. This table will show the details of each parameter with the unit:

MQ-7 Carbon Monoxide Sensor Applications

Carbon monoxide is used in different industries in such places, so using the sensing system is a must. Here are some general examples where the MQ-7 carbon monoxide can be integrated for the detection:

• Air quality monitoring

• Industrial safety

• Home and office safety systems

• Environmental monitoring

• Combustible gas detection

• Automotive emissions monitoring

• Gas leak detection systems

• Portable gas detectors

• Agricultural and greenhouse applications

• HVAC systems

Hence, today we have read the details of a life-saving sensor that is MQ-7 carbon monoxide sensor. It is used in multiple projects and we started learning through its introductions and details of its internal components. After that, we saw the datasheet elements like its specifications, features, and some important information about its structure. just after that, we read about its working principle, physical dimensions and some important applications where this sensor can be used. I hope all the points are clear to you but if you want in-depth information then you can ask in the comment section.

MQ-6 LPG Butane Gas Sensor: Datasheet, Pinout & Working

Hey pals! Welcome to the next article where we're studying a gas sensor from the MQ sensor series. Today, we’ll understand the MQ-6 LPG butane gas sensor and will know the basic information about this product. This sensor has sensitivity for gases like LPG, isobutane propane etc and it is widely used to check any leakage of these gases. These are the commonly used gases but any leakage or excessive use may be harmful and even life-threatening. In such cases, sensors like MQ-6 are proved one of the most important devices. 

In this article, we’ll start the discussion with the introduction of the MQ-6 LPG butane gas sensor. After that, we’ll move towards the datasheet of this product in which we’ll study the specifications, features, and some graphs that will show its working. After that, we’ll work on the working principle and physical dimensions of this sensor and in the end, we’ll see some common examples of the applications in which this sensor is widely used.

Let’s move towards the first topic:

MQ-6 LPG Butane Gas Sensor Introduction

Butane gas is not only used in houses but has a major role in multiple industries where it is used as a fuel. It is a common source of energy for factories but using safety precautions is the most important point to keep in mind and here, the duty of the sensor like MQ-6 starts. The MQ-6 LPG butane sensor detects the presence of leakage in the gases and provides the information in the form of analog values so that the user may know the amount of the gas present in the surroundings. 

At the core of this gas sensor, there is a small and sensitive structure of different components that allow it to detect the LPG butane gas from the surroundings with the help of a change in the electrical conductivity. The basic components of this sensor are:

• Micro AL2O3 ceramic tube

• Sno2 (tin dioxide) layer

• Measuring electrode

• Heater

• plastic and stainless steel net

• Base

These components collectively prepare a small sensor compatible with different types of circuits. The following are the gases that can be detected using the MQ-6 LPG butane gas sensor:

• Butane (C4H10)

• Propane (C3H8)

• Methane (CH4)

• Alcohol vapors

• Benzene

• Carbon monoxide (CO)

• Hydrogen (H2)

• LPG (Liquefied Petroleum Gas)

The sensitivity of the MQ-6 sensor varies according to the type of the gas. 

MQ-6 LPG Butane Gas Sensor Datasheet

Before using any electrical component, always check the datasheet for detailed information on the product. In the case of the MQ-6 LPG butane gas sensor, here are the important points that one must know:

MQ-6 LPG Butane Gas Sensor Features

• As mentioned before, this sensor has a high sensitivity to LPG, iso-butane, propane and other similar gases. 

• It has a small sensitivity to gases like alcohol, and smoke but is not suitable to be used as only a sensor for these gases.

• This sensor shows a fast response so is a reliable choice.

• It works continuously therefore providing stable results and having a long life.

• This sensor runs on the simple drive circuit

• As soon as it is turned on, it takes only 20 seconds to preheat and starts working.

• It can be used as a Digital or analogue sensor because it has both pins

• The user can vary the Sensitivity of the digital pin using the potentiometer in its structure

MQ-6 LPG Butane Gas Sensor Specifications

The following table is the evidence of its different specifications regarding different types of parameters:

MQ-6 LPG Butane Gas Sensor Basic Structure

The basic compoeents of the MQ-6 LPG butane sensor have been discussed before but now, let’s have a look at the internal structure of this sensor to understand its working. Here is the circuit diagram for this purpose:

The detail of each label and its description is written here in the table below:

MQ-6 LPG Butane Gas Sensor Sensitivity Characteristics

The MQ-6 LPG butane gas can detect multiple gases but the sensitivity varies according to the type of the gas. With the help of continuous experimentation, the sensitivity of this detector can be examined using the graph given below:

Here, other parameters such as temperature and humidity are kept constant. The above image shows the sensitivity of the MQ-6 LPG butane gas sensor in the range of 100-1000 ppm. Here, 

Rs:

• It stands for sensing resistance.

• It represents the actual resistance of the sensor in the presence of a specific gas concentration.

• It changes based on the gas concentration which decreases as the concentration increases.

Ro:

• It stands for Reference Resistance.

• It represents the sensor's resistance in clean air (absence of target gases).

• It is usually measured when the sensor is powered on and heated to operating temperature in a gas-free environment.

Rs/Ro:

• It represents the ratio of sensing resistance (Rs) to reference resistance (Ro).

• This ratio provides a normalized value to compare the sensor's response across different gas concentrations and environmental conditions.

• The higher Rs/Ro values generally indicate the presence of higher gas concentrations.

If you want to have more detail about its datasheet you can visit the link below and get all the information:

MQ-6 LPG Butane Gas Sensor Pinout Configuration

The four-pin MQ-6 butane gas sensor is easy to install and has the simple pin configuration that is mentioned in the table below:

MQ-6 LPG Butane Gas Sensor Packages

For the convenience of the users, the MQ-6 LPG butane gas sensor is present in different types of packages. Here is a brief introduction of these:

MQ-6 LPG Butane Gas Sensor Alternatives

The butane is a widely used gas, therefore, there are different alternatives present in the market that have the same good performance as the MQ-6 LPG butane. Some of these belong to the MQ family and others are from different classes. Here are some alternatives:

Metal Oxide Semiconductor (MOS) Sensors

• MQ-2

• MQ-3

• MQ-4

• MQ-5

• MQ-7

• MQ-8

• MQ-9

• MQ135

Electrochemical Sensors

• MiCS-5525/5526

• SGX Sensortech MiniMOS

• CityTech SEN5X

Infrared (IR) Sensors

• Senseair NDIR sensors

• SGX Sensortech IR sensors

Where to Buy MQ-6 LPG Butane Gas Sensor?

The electrical components are delicate and the performance varies because of different parameters. Here are some platforms where you can have the best quality MQ-6 LPG butane gas sensors:

• eBay

• AliExpress

• Amazon

MQ-6 LPG Butane Gas Sensor Working Principle

The working of the MQ-6 LPG butane gas sensor is similar to the other MQ sensors. I have divided the working principle into different steps and will understand the basic flow:

MQ-6 LPG Butane Gas Sensor Heating Process

When the sensor is turned on, the circuit starts heating the core of this sensor that has the sensitive element SnO2 layer. This process is done to maintain a temperature of around 300°C (572°F) which activates the sensing element and it starts absorbing the oxygen from the surrounding air. 

MQ-6 LPG Butane Gas Sensor Ion Creation

The result of the reaction in the previous step creates the depletion region around the sensing element. As a result, the electrical conductivity of the circuit decreases because of the high resistance.

MQ-6 LPG Butane Gas Sensor Gas Absorption

Once the MQ-6 LPG sensor comes into contact with the target gas, the oxygen ions from the depletion region start reacting with the gas molecules and as a result, the depletion region starts adsorbing. This causes the reduction in the number of oxygen ions and the overall conductivity increase.

MQ-6 LPG Butane Gas Sensor Resistance Measurement

The circuit of the sensor measures the change in the resistance and the electrical current as well. The change in the current is directly proportional to the amount of the target gas in the environment. In this way, the analog values are sent to the output device through the analog output pin.

MQ-6 LPG Butane Gas Sensor Digital Output

The MQ-6 provides the feature of digital output as well. The analog values, when exceeding the threshold value set through the potentiometer, are converted into the digital output and the sensor sends the signal through the digital pin. This is useful because usually, this pin is connected to the alarm and in the systems like an automatic alarm that shows the signal of the LPT butane gas presence.

MQ-6 LPG Butane Gas Sensor Physical Dimensions

MQ-6 LPG Butane Gas Sensor Applications

Here is a list of simple and basic examples that show the applications where the MQ-6 LPG butane gas sensor is extensively used:

Gas Leak Detection

• Homes
• Industries
• Vehicles

Air Quality Monitoring

• Indoor environments
• Industrial settings

Combustible Gas Safety Systems

• Appliances
• Furnaces
• Leak detection alarms

Environmental Monitoring

• Landfill gas detection
• VOC monitoring

Portable Gas Detection Devices

• Personal safety monitoring
• Industrial inspections

Research and Development

• Flammable gas sensing experiments
• Sensor evaluation and comparison

So, we have studied the MQ-6 LPG butane sensor in detail. We have started our discussion with the basic introduction of this sensor. We’ve seen the gases it can detect, the details of the datasheet, its pinout configuration, working graphs, its internal features, and the working principle in detail. After that, we saw the alternatives and package details along with the physical dimension of this sensor. In the end, we saw examples of different domains where this sensor is widely used. I hope I have covered all the points and you like the content. 

MQ-5 Natural LPG Sensor: Datasheet, Pinout & Working

Hi readers! Welcome to another article where we are discussing the MQ family members. Today, our motto is to learn about the MQ-5 natural liquified petroleum gas (LPG) sensor. The gas sensing material used in this sensor is known as tin dioxide(SnO2). It detects the natural LPG in the surroundings as soon as the core material of this sensor comes in contact with the LPG. This will be explained in simple words in this article.

Today, we’ll start learning about the basic introduction of the MQ-5 natural LPG sensor. After that, we’ll move towards its datasheet element, where we are going to see the specifications and features of the sensor, along with the pinout configuration and internal structure. We’ll also see the working principle and applications of the MQ-5 natural LPG sensor, and all the information will be shown by using tables, descriptions, and images for the best concepts.

So, let’s dive into the first topic to move forward:

MQ-5 Natural LPG Sensor Introduction

The MQ-5 natural LPG sensor belongs to the class of sensors that are used for the detection of different gases. The MQ-5 natural LPG sensor can detect multiple gases with the help of the semiconductor material tin dioxide (SnO2) present in its basic structure. This material has low conductance in pure gas (with no natural LPG), but as soon as it comes into contact with the natural LPG, the electrical conductance decreases, which is indicated through the output pin of this sensor. The simple circuit of this sensor converts this change in conductivity into a voltage change, and as a result, these sensors can send the signal to other components of the circuit to stimulate the system.

Here is a simple list of the detectable gases using an MQ-5 natural LPG sensor:

• Propane (C3H8): MQ-5 has the highest sensitivity for propane gas, making it suitable for propane leak detection. This is the primary gas for MQ-5 natural LPG sensor detection.
• Methane (CH4): The sensor has some sensitivity for methane as well, but not as precise as dedicated methane sensors. If the user wants to have a highly precise sensor for methane, then MQ-4 is a better option.
• Butane (C4H10): The butane gas is also detected using this sensor if the gas includes Liquefied Petroleum Gas (LPG).
• Alcohol (C2H5OH): For alcohol gas, this sensor has limited sensitivity. It is not ideal for precise alcohol measurements, but if the user wants a precise result, they can use the MQ-3 sensor.
• Hydrogen (H2): The MQ-5 has some sensitivity for hydrogen presence as well, but potential interference from other gases.

MQ-5 Natural LPG Sensor Datasheet

Before going into the details of its external structure, it is better to know about the internal features and specifications of this product. Here are some important features of the MQ-5 sensor that make it a good choice for natural LPG detection:

MQ-5 Natural LPG Sensor Features 

• The first and most obvious feature of this sensor is, that it is highly sensitive to propane (C3H8); therefore, the primary goal of this sensor is to detect any liquified petroleum gas (LPG). 

• The internal structure is designed in such a way that it responds to the LPG as soon as the sensitive internal material comes into contact. 

• It requires simple additional circuitry to create the whole system, and its design is easy to integrate with other components. 

• It has low power consumption and, therefore, is a suitable component of projects like the Internet of Things (IoT). Here, it can work continuously, and the simple structure is the reason behind its long life. 

• It provides stable results and readings over time and, therefore, is a reliable component. 

MQ-5 Natural LPG Sensor Specifications

MQ-5 Natural LPG Sensor Structure

Before going into the details of the external structure, let’s have a look at the internal structure of this sensor:

The image shown above displays the structure of the dimension from different angles of the sensor. The unit here is a millimeter, and all the readings have a tolerance:±0.1mm. We’ll learn the detailed dimensions soon in this article. 

MQ-5 Natural LPG Sensor Basic Circuit

An important feature of this sensor is its simple circuit, which not only makes it less power-consuming but also allows the user to install it without any complications. Here is the basic structure of this LPG sensor:

The labeling of the image will be clarified in the next section when we study its structure in detail.

If you want to study the datasheet in more detail then I suggest you visit the following link:

MQ-5 Natural LPG Sensor Pinout Configuration

Just like most of the gas sensors of this class, MQ-5 has four pins. In some models, the additional two pins are also present. It has a simple structure, and the detail of each pin is given in the table below:

MQ-5 Natural LPG Sensor Packages

A plus point of this series is, the gas sensors come in different packages so that the user may choose MQ-5 natural LPG sensor according to the type of circuit. Each package has its own pros and cons.  Here are some important packages in which this sensor is available:

MQ-5 Natural LPG Sensor Alternatives

Some other gas sensors from the MQ series can be used in place of the MQ-5 natural LPG sensor, but these may not be that efficient. Here are some popular gas sensors that can be used in place of MQ-5 natural LPG sensors:

• Semiconductor sensors (propane, butane, and carbon monoxide)
• Metal oxide semiconductor (MOS) sensors (ammonia, hydrogen sulfide)
• NDIR (non-dispersive infrared) sensors (methane, CO2)
• Catalytic bead sensors (combustible gases)

Where to Buy MQ-5 Natural LPG Sensor

The electronic components are sensitive, and the performance depends on the circuit and the manufacturing features. If you want to get the best MQ-5 natural LPG sensor, you must buy it from the following platforms:

• eBay

• AliExpress

• Amazon

MQ-5 Natural LPG Sensor Working Principle

The MQ-5 sensor has a similar working as other gas sensors from the MQ series. The sensor detects LPG and methane gases through the semiconductor metal oxide sensing layer. Here is the breakdown of the work into different steps:

MQ-5 Natural LPG Sensor Heating Process

The MQ-5 has a heating element in its core that is constantly powered. Typically, it is done on the 5V and this heating enables the sensing layer to absorb more gas molecules from its surrounding air. Usually, the sensing element is tin dioxide (SnO2) because it is an excellent receptor of flammable gases.

MQ-5 Natural LPG Sensor Ion Creation

The constant heating allows the reactive material to absorb oxygen and create oxygen ions on its surface. In this way, these ions are readily available for the flammable gases needed for the reaction. As a result, a depletion region is formed around the tin oxide so that the electrical resistance of the circuit increases. 

MQ-5 Natural LPG Sensor Gas Adsorption

As soon as the reactive gases (LPG) come into contact with the oxygen ions, these start reacting with the liquified petroleum gas. This results in a decreasing number of ions and a decrease in electrical resistance. We know that the electric current is inversely proportional to the resistance so the overall electrical conductivity of the circuit is affected, which causes the sensing of the gas.

MQ-5 Natural LPG Sensor Analogue Values

The circuit is designed in such a way that the change in the current values stimulates the analog output that can be detected at the analog pin as an output.

MQ-5 Natural LPG Sensor Digital Output

Some models of MQ-5 have a digital output as well. The change in the electrical current causes a change in the voltage difference between the diodes of the circuit. This voltage change is detected on the digital pin of the MQ-5 natural LPG sensor. This happens because the circuit has an analog to a digital converter.

The voltage change typically ranges from 2.5V to 4.0V. As the concentration of the LPG and other reactive gases increases, it causes a change in the electrical conductance and as a result, less voltage change is seen.

MQ-5 Natural LPG Sensor Physical Dimensions

A feature of this sensor is its small and compatible size, which can fit in different circuits. Here are the dimensions of the MQ-5 natural gas sensor that will help you work with it in a circuit:

MQ-5 Natural LPG Sensor Applications

There are different ways to use this sensor in applications. This is a common gas sensor in different domains of daily life. The basic and most common examples of its applications are given here:

• Industrial flammable gas alarm

• Portable gas detector

• Domestic gas leakage alarm

• Air quality monitor

• Educational projects

• Smart home devices

• Robotics

• Automotive

• Agriculture

• Healthcare

Hence, in this way, we have studied the mQ-5 natural LPG sensor in detail. We started this learning through the basic introduction of this sensor. We saw that it can detect multiple gases but it is most precise for the MQ-5 natural LPG. We studied the basic features and specifications through its datasheet and saw different graphs to understand its working. Just after that, we understood the pin configuration and working principle of this sensor. In the end, we saw the table for the physical dimension and the applications of this gas sensor. I hope I have covered all the topics but if you want to learn more, you can ask us.

MQ-4 Methane Gas Sensor: Datasheet, Pinout & Working

Hello readers! I hope you are doing great. Today we are discussing the features and details of the MQ-4 methane gas sensor, which belongs to the popular gas sensor MQ family. We have been working on other gas sensors as well, but MQ-4 is particularly suitable for detecting the presence of methane gas. This sensor is more popular because methane gas and compressed natural gas (CNG) are widely used for cooking and other related purposes. MQ-4 methane gas sensor is an important part of the home safety system.  Some other advantages of this sensor are, that it responds instantly and has a potentiometer that adds versatility to its functions. 

In this article, we are going to study the MQ-4 methane sensor from scratch. We’ll go through its introduction and will study the basic components of its datasheet. We’ll see some performance graphs and study the internal structure of this sensor. After that, we’ll move towards the external circuit and its working features. In the end, there will be a study of its applications. This is going to be an easy and informative article, so let’s move on to the first point:

MQ-4 Methane Gas Sensor Introduction

Methane gas is widely used everywhere, and we’ve seen multiple cases of gas leakage. Therefore, the MQ-4 methane gas sensor has a special place in different applications in almost every domain of life. The MQ-4 methane gas sensor is a metal oxide semiconductor (MOS) that detects the presence of methane gases and then provides the result in the form of analog values. In this way, it provides information about the gas concentration, and its range is 300 ppm–10,000 ppm which is enough to detect leakage.

The basic structure of this gas sensor includes the following:

• A double mesh network
• Detecting element
• Pins
• Firm base

The sensitivity of this detector for different gases may vary but overall, it is a good choice for detecting any gas leakage. This sensor can detect gases like:

• Methane (CH4)
• Ethanol (C2H5OH)
• Liquefied petroleum gas (LPG)
• Benzene (C6H6)
• Smoke

The ignition of these gases is extremely exothermal, so these produce a large amount of what. Therefore, the MQ-4 methane sensor is a life-saving element. 

MQ-4 Methane Gas Sensor Datasheet

Till now, we have seen the basic features of this sensor but now, we are going to discuss the details of its functions. Here are some important points that will highlight the importance of this sensor:

• The primary function of the sensor is to detect methane (CH4 ) gas. It is highly sensitive to methane and other natural gases; therefore, it is widely used to detect gas leakage.
• It has some sensitivity for gases like ethanol (C2H5OH) but is not an ideal choice for it. For the best precision of such gases, the MQ-3 alcohol sensor is used.
• Another gas that MQ-4 can detect is liquefied petroleum gas (LPG). It also includes propane (C3H8) and butane (C4H10).
• Other gases detected by this sensor are benzene (C6H6), which is an aromatic hydrocarbon with potential health risks, and smoke (which may trigger incomplete combustion products).
• This sensor has a fast response time with a very small recovery time.
• It has a long life, and it provides suitable performance all the time.
• It has a compact size and an easy-to-integrate design.
  

MQ-4 Methane Gas Sensor Specifications 

There are multiple types of specifications, and I’ve divided them into different groups for clarification. Here is the table that shows the standard work condition parameters and their details:

Now, here are some important environmental parameters for the MQ-4 methane sensor:

The sensitivity characteristics of this sensor, along with important parameters, are given below:

MQ-4 Methane Gas Sensor Structure

The internal structure of the MQ-4 methane sensor is similar to that of its other daily members. Here is the detailed internal structure diagram that will help you understand the information we’ll discuss in the next section:

As discussed before, the MQ-4 methane sensor has different sensitivity levels for different gases. Based on multiple experiments, here is the graph that describes the sensitivity results:

The temperature and humidity around the MQ-4 methane sensor play a crucial role in the performance scale. Here is the graph that shows the change in the sensor’s behavior with varying temperatures and humidity:

Here, 

Rs = The sensing resistance that depends on the concentration of the target gas. In the case of MQ-4, the target gas is methane. 

R0 = The resistance of the sensor in clean air. It is the baseline resistance of the sensor when there is no methane present in the air. 

Rs/R0 = It is the ratio of sensing resistance to the resistance in clean air. It is calculated to understand the relative change in the resistance of the sensor, and it depends on the target gas concentration.

If you want to see the detailed datasheet of the MQ-4 methane gas sensor, then you can visit the link MQ-4 Methane Gas Sensor.

MQ-4 Methane Gas Sensor Pinout Configuration

Now, it is time to discuss the external structure of this sensor. Just like most of the members of the MQ sensors, this sensor has four pins. The name of each pin and its function are given in the table below:

MQ-4 Methane Gas Sensor Packages

For the convenience of the user, the MQ-4 methane sensor comes in different packages. Here is the table that will show a brief introduction to the available packages:

MQ-4 Methane Gas Sensor Alternatives

Here is a list of some other alternatives that are used in place of the MQ-4 methane gas sensor, along with the types of gases these can sense:

• Electrochemical sensors
• Photoionization detectors (PIDs)
• Tunable diode laser (TDL) sensors
• Semiconductor sensors (propane, butane, and carbon monoxide)
• Metal oxide semiconductor (MOS) sensors (ammonia, hydrogen sulfide)
• Semiconductor sensors (propane, butane, and carbon monoxide)
• Metal oxide semiconductor (MOS) sensors (ammonia, hydrogen sulfide)
• NDIR (non-dispersive infrared) sensors (methane, CO2)
• Catalytic bead sensors (combustible gases)

Where to Buy MQ-4 Methane Gas Sensor

The MQ-4 methane gas sensor is a common instrument available on multiple platforms, but one must always choose reliable sources. These sensors are proven to be life saviors, so I would suggest you buy them from the options given below:

• eBay

• AliExpress

• Amazon

MQ-4 Methane Gas Sensor Working Principle

The working principle of the MQ-4 methane gas sensor is similar to that of the other MQ sensors. Let's discuss each component of this sensor and its role in the final result:

MQ-4 Methane Gas Sensor Basic Working

The basic workings of the MQ-4 methane gas sensor depend on the electrical conductivity of the metal oxide semiconductor (MOS) material used in the structure of this sensor.

The MOS is also known as the chemiresistors, which means the electrical conductivity changes when these come into contact with the gas vapors. 

MQ-4 Methane Gas Sensor Heating Element

The sensor has a heating element at its core, the duty of which is to maintain a constant heating temperature of around 300°C. This is a crucial process for the right response of the sensor. 

MQ-4 Methane Gas Sensor Methane Adsorption

As soon as the methane gas comes into contact with the metal oxide semiconductor (MOS), it is absorbed onto its surface. The surface already has oxygen ions, and when these ions contact the vapors, they start reacting with them.

MQ-4 Methane Gas Sensor Conductivity Change

The reaction between the oxygen ions and methane results in a decrease in the conductivity of the MOS layer. This change is directly proportional to the amount of methane present in the surrounding air of the MQ-4 methane gas sensor.

MQ-4 Methane Gas Sensor Output 

The change in conductivity resulting from the previous step is measured as the change in voltage across the sensor electrodes. The greater the resistivity change, the greater the voltage change across the electrodes. 

MQ-4 Methane Gas Sensor Physical Dimensions

Here is the table that shows the physical dimensions, their values, and additional notes of these parameters:

MQ-4 Methane Gas Sensor Applications

Till now, we have been discussing the basic output of the MQ-4 methane gas sensor but now, we’ll understand how this small instrument can be used in different ways to get the required output. Here are some important examples of applications where an MQ-4 methane gas sensor is used as the heart of the circuit:

• Natural gas leak detection (home and industrial)
• Ethanol detection
• Liquefied petroleum gas (LPG) detection
• Benzene detection
• Smoke detection
• Air quality monitoring (broad VOC/combustible gas detection)
• Educational projects (learning gas sensing, basic electronics)

So, today we have seen the details of the MQ-4 methane gas sensor. We started with the basic introduction of this sensor and then saw the basic points of its datasheet. After that, we’ve seen the pin configuration and workings of this sensor. We understood every step of its operation and saw the physical dimensions of this methane gas sensor. In the end, we give some important examples where the MQ-4 methane gas sensor is used as the base. I hope you have understood each point, but if something is confusing, you can ask questions in the comment section.

MQ-3 Alcohol Sensor: Datasheet, Pinout & Working

Hey readers! I hope you are having a good day. Today, we are learning the basics of another MQ sensor family, the MQ-3. This sensor is designed for the detection of alcoholic gases in the air surrounding it. Gas sensors are widely used in multiple applications, and they provide information to the other components of the circuit. In the air, it can detect the 25-500ppm alcohol gas concentration and is a highly sensitive detector. We are going to study it thoroughly from scratch. 

In this article, we are going to start the discussion with the basic introduction of this sensor. We’ll understand its datasheet and will know the basic details about its internal and external structure. After that, we’ll move towards the features, specifications, and best platform to buy these sensors. Then, we’ll see the circuit diagram and working principles, and in the end, we’ll go through the applications of this sensor. All of this is going to be very simple, and we will try to make it useful and uncomplicated. Let’s move on to the first topic:

 MQ-3 Alcohol Sensor Introduction

The MQ-3 is an alcohol gas sensor that belongs to the MQ gas sensor family and is particularly designed using SnO2 to detect the gas using lower electrical conductivity in the air. When fresh air enters the sensor’s structure, this semiconductor gas sensor can detect the presence or absence of alcohol gases. If the target gas is present in the air, the resistance of the semiconductor material is enhanced with the rise in gas concentration. The structure is designed in such a way that it has a high sensitivity to alcohol. Moreover, it has good resistance to gasoline, smoke, and vapors.

The following gases are possible to detect using an MQ-3 alcohol sensor:

• Ethanol (primary target gas)
• Aromatic hydrocarbons:
• Toluene
• Benzene
• Xylene
• Chlorinated hydrocarbons:
• Trichloroethylene
• Dichloromethane
• Amines

MQ-3 Alcohol Sensor Datasheet

The MQ-3 alcohol sensor is studied in different ways. Here are the three tables that will define the specifications of this sensor depending on different sets of parameters:

Standard Work Conditions

In the standard work condition, the characteristics given in the table below are considered:

MQ-3 Alcohol Sensor Environmental Conditions

The following parameters are considered when checking the environmental characteristics of the MQ-3 alcohol sensor:

MQ-3 Alcohol Sensor Sensitivity Characteristics

Moreover, here is the table related to the sensitivity characteristics of the MQ-3 alcohol sensor:

MQ-3 Alcohol Sensor Structure

Before learning the structure diagram, it is important to understand the configuration of the sensor. It contains three sets of pins (collectively six pins):

The above images show the 2D configurations of the MQ-3 alcohol gas sensor. The details of these pins will be discussed in the table below:

MQ-3 Alcohol Sensor Sensitivity Curve

The core material in these gas detectors is highly sensitive to heat which plays an important role in gas detection. Before using any sensor, it is crucial to check its sensitivity graph. Here is the graph for the MQ-3 alcohol  sensor:

In the figure above, the parameters used are understood by the following explanation:

1. The Rs is the sensor’s resistance when it is exposed to a particular alcohol vapor concentration. The increase in concentration results in a decrease in Rs, and vice versa.
2. The R0 determines the sensor’s resistance in clean air when no alcohol is present in it. Hence, it is used as the baseline reference when dealing with the comparison between conditions.
3. The ratio of both of these is an estimation of the relative change in resistance. It is proportional to the alcoholic concentration in the air and, therefore, is helpful for the sensor’s working.

So it was the information about the datasheet, and if you require more details, then you visit the following link:

MQ-3 Alcohol Sensor Pinout Configuration

The MQ-3 alcohol sensor has four external pins, and its pin diagram is given here:

A brief description of each of them is given in the table:

MQ-3 Alcohol Sensor Packages

MQ-3 Alcohol Sensor Alternatives

The MQ gas sensor family works on the detection of different gases. In some cases, these can be used alternatively. But if we talk about the other classes of gas sensors, some other detectors can be used in place of the MQ-3 sensor, and these are listed below:

• Electrochemical Sensors
• Metal Oxide Semiconductor (MOS) Sensors: MQ-135, MQ-303A
• Photoionization Detectors (PIDs): MiniPID 2, ppbRAE 3000
• Infrared (IR) Sensors: Figaro TGS822, Sensirion SENSPAIR SFK-D8
• Tunable Diode Laser (TDL) Sensors: Gasmet Dx4340, Aerodyne QCL-32

Where to Buy MQ-3 Alcohol Sensor

There are different ways to buy electronic components like MQ-3 but the most promising platforms to buy these products online are:

• eBay
• AliExpress
• Amazon

MQ-3 Alcohol Sensor Working Principle

The working principle of the MQ-3 alcohol sensor can easily be understood by learning its internal structure. It is a heat-driven sensor and, therefore, is covered under the mesh known as the anti-explosion network. This network is the double layer of the stainless steel material that ensures the heat-sensitive material inside the sensor remains safe from the outside’s flammable gases. The special feature of its structure is the presence of a plastic cover that we don't see in models like MQ-2. This cover not only protects the sensor but is also responsible for filtering unwanted materials.

• Inside this mesh, there is a simple star-like structure of the sensing material surrounded by the size elements. These are called the connecting legs and consist of three pairs of leads. The two H leads are connected to the Nickel-Chromium coil. It is a popular conductive alloy that helps to maintain the connection between the star-structured elements. 

The remaining leads (A and B) are connected with the sensing element. All of these are connected together with the help of platinum wires that make the structure more protected and provide conductance as well. 

In the case of the MQ-3 alcohol sensor, aluminum oxide (AL2O3) ceramic with a tin dioxide coating (SnO2). is used in the form of a tubular structure and is known as the sensing element. It is important to notice that tin oxide is the most important element here because it is sensitive to alcohol, which is the basic purpose of this sensor. The role of aluminum oxide is to improve efficiency and heat sensitivity. It maintains the continuous heating of the system and, as a result, helps in efficient results. 

Now, that you know the basic structure, you can understand the flow of the MQ-3 sensor:

• When the MQ-3 alcohol sensor is turned on, the circuit heats the internal structure of the sensor. As a result, the SnO2 layer is at a high temperature. It results in the absorption of oxygen from the surrounding air.
• This results in a depletion region around the sensing element that creates a potential barrier. This barrier makes the sensitive element more resistive, so the electric flow is affected.
• When the alcohol gas is present surrounding the sensor, the electrical resistance decreases because alcohol reacts with the sensing element’s depletion region.
• The change in the electrical resistance is inversely proportional to the current flow; therefore, the change in current results in the detection of alcohol gas.
• The higher the alcohol concentration in the air, the higher the values obtained at the analog pin.
• The analog values can be converted into digital output using the LM393. It is a high-precision comparator that converts the values, and, as a result, the digital values are present at the D0 pin.
• This module also has a built-in potentiometer that has the feature of setting threshold values. As a result, the module will show a low output unless the values reach the threshold.

MQ-3 Alcohol Sensor Physical Dimensions

The physical dimension of the MQ-3 alcohol sensor is similar to that of its other companion sensors. These are mentioned in the table below:

MQ-3 Alcohol Sensor Applications

The MQ-3 is designed to test the presence of alcohol-related gases. It is usually the part of the project that is designed for safety purposes. Here are some common applications for which MQ-3 is a popular choice:

• Basic breathalyzer (informative, not legal/professional)
• Air quality monitoring (broad VOC/combustible gas detection)
• Home gas leak detection (limited, not specific)
• Educational projects (learning gas sensing, basic electronics)
• Non-critical industrial gas detection (budget option)

One must keep in mind before using this sensor that it is not an accurate sensor and certain limitations are tied to it. Therefore, it is not suitable for critical applications that require precise measurements.

Hence, today we have learned a lot about the MQ-3 alcohol sensor. It is a sensitive alcohol detector that is used to detect multiple gases. We have seen the data sheet of this sensor, where we have seen the pin configuration, working conditions, and internal structure of the MQ-3 alcohol sensor. After that, we saw the working principle in detail, and after knowing the physical dimensions, we saw the applications of this sensor. I hope I have conveyed all the points, but still, if you want to know more, you can ask in the comment section.

MQ-2 Smoke/Gas Sensor: Datasheet, Pinout & Working

Hello learners! I hope you are doing good. Today, we are learning about an important member of the gas sensor family, which is the MQ-2. When it comes to detecting or measuring smoke or gas, the MQ series gas sensors are widely used components in circuits. These sensors come with an operational amplitude comparator and a digital output pin therefore, they have applications in multiple fields of life. Mostly, it is used in Arduino projects where it senses the gas and the information is fed into the Arduino to allow the circuit to work according to its digital output. 

In this article, we are going to discuss the basic introduction of this sensor in detail, along with the datasheet. Moreover, we’ll know its pinouts in detail and will see some important circuit diagrams. Moreover, we’ll try to figure out the workings and applications of this sensor in different domains to understand the core concept. This is going to be a detailed article on the MQ-2 sensor, so let’s get started.

MQ-2 Smoke/Gas Sensor Introduction

The MQ-2 is a metal oxide semiconductor (MOS) gas sensor and one of the most widely used sensors in the MQ series. We know that MOS sensors are known as Chemiresistors because there is a sensing material in them that works based on the change in its resistance when it is exposed to the reactive gas. Hence, when using the MQ-2 in the circuit, it can detect multiple gases and provide the digital values of change in the gases at its output pin. The list of gases this sensor can detect is given next:

• Liquified petroleum gas (LPG)
• Smoke
• Alcohol
• Propane
• Hydrogen
• Methane
• Carbon Monoxide

This sensor is particularly suitable to detect combustible gases, smoke, and other pollutants. Basically, it consists of the tin dioxide (SnO2) semiconductor gas sensor, a comparator (using the op-amp), and necessary supporting components.

MQ-2 Smoke/Gas Sensor Datasheet

Before using any electrical component, it is important to study its datasheet. The datasheet has multiple characteristics, and some of these are mentioned below:

MQ-2 Smoke/Gas Sensor Basic Parameters

Here is a table that provides the basic details of the MQ-2 smoke/gas sensor:

MQ-2 Smoke/Gas Sensor Sensitivity Graph

The sensors can detect multiple gases, and the sensitivity of the resistive material is different for all of them. Based on the multiple experiments and the specification, here is the sensitivity graph for the MQ-2 smoke/gas sensor:

MQ-2 Smoke/Gas Sensor Sensitivity Graph

The sensitivity material is affected not only by the type of gas but also by other parameters such as humidity and temperature. Here is the graph that shows the details:

If you want to know more details about the datasheet, then here is the link to it:

MQ-2 Smoke/Gas Sensor Pinout Configuration

The MQ-2 smoke/gas sensor has four pins, as shown below in the image:

The pin arrangement may vary depending on the model. Here, one must know that the DOUT pin is not always present, but some models do not have it, and in such cases, the analogue pin AO is the output pin. The details of each pin are given next:

The internal structure is shown below to add more detail in this discussion:

MQ-2 Smoke/Gas Sensor Packages

MQ-2 Smoke/Gas Sensor Alternatives

In addition to all these, the MQ series has multiple members that are widely used in place of MQ-2. These may include 

Where to Buy MQ-2 Smoke/Gas Sensor 

Along with millions of other products, sensors like MQ-2 smoke/gas sensors are available at the following platforms:

1. eBay

2. Amazon

3. AliExpress

MQ-2 Smoke/Gas Sensor Working Principle

The working principle and characteristics of the MQ-2 are easily understood by studying the internal structure in detail. Here is the detail of each part, and we’ll discuss the working principal using the following structure:

As mentioned before, the MQ-2 smoke/gas detector works on the principle of chemisorption. It is defined as:

"Chemisorption is the process by which the molecules of the material adhere to the solid surface because of the chemical bonding."

In the case of MQ-2, chemisorption is the process in which the gas molecules surrounding the sensor interact with its surface material and cause a change in the electrical resistance. 

It is a heat-driven sensor, therefore it is covered with two layers of steel mesh. These layers are referred to as the anti-explosion network. This sensor is designed to detect combustible gases; therefore, the anti-explosion network is responsible for the protection of the heater element from the surrounding gases.

This network is in the form of a mesh so that it filters the suspended articles and allows only gases to reach the internal sensitive circuit. A copper plating is used to secure the mesh at its place.

When the mesh is removed, the following structure is seen:

This star-shaped structure is responsible for the detection of the gas. Here is the explanation of each element:

• The sensing element lies in between all the other elements. It has a coating of tin oxide (SnO2), which is heated to 200-300 °C. This temperature activates the sensing element so that it may absorb the oxygen from the surrounding air. As a result, a depletion region is formed that increases the overall sensor resistance.
• The H indicated the sensing element heaters. Usually, it is a Nickel-Chrominum coil (conductive alloy).
• The A and B are the signal-carrying leads that are connected with the platinum wires. Through these wires, the A and B connect with the sensor element body. These are responsible for the small changes in the current values.

Once the gas enters this internal chamber, it reacts with the depletion region of the sensing element. As a result, the amount of oxygen decreases depending on the amount of the external gas, and as a result, there is a change in the resistance. The magnitude of this change determines the amount of combustible gas surrounding the gas sensor.

The sensor has a voltage divider circuit that converts the change in resistance into the output voltage, which is then sent as an output through the pin.

MQ-2 Smoke/Gas Sensor Features

Most features of this sensor have been discussed so far in this article, but here is a quick revision of these features:

• It detects the combustion gases around it, and the structure is protected through an anti-explosion network. The other gases surrounding the sensor do not have any effect on its working in normal conditions.
• In most of the models, there is only the analogue pin, whose value is potentially related to the detectable gas concentrations.
• Some modules have a digital output as well, which is indicated by DOUT.
• The calculation of the resistance in this case is followed by the formula given next:

This is a simple-to-use sensor that is compatible with multiple circuits. Another feature that supports its importance is its low cost and high-quality performance.

MQ-2 Smoke/Gas Sensor Physical Dimensions

The following table shows the dimensions of this sensor:

MQ-2 Smoke/Gas Sensor Applications

The smoke and gas detector sensors are used in different ways in the project and are one of the most important parts of such circuits. Here are some basic examples of MQ-2 smoke/gas sensor applications:

• Residential gas leak detection (homes)

• Industrial gas leak detection (factories)

• Basic fire alarm systems (buildings)

• General air quality monitoring (sensor network)

• Portable gas detectors (personal safety)

• Educational electronics projects

Hence, today we have learned the basic information and its detailed specifications. We started with the basic introduction of the MQ-2 sensor and how it works. We understood its features, and workings and read the datasheets. In the end, we see some simple applications in different domains of life. I hope this was an informative guide for you, and if you want to add more information in it, you can comment to us.

INA219 Current Sensor Module Datasheet, Pinout, Features & Applications

Hi Friends! Hope you’re well today. I welcome you on board. Today, I’ll walk you through the Introduction to INA219.

The INA219 is a current sensor module that incorporates the I2C protocol for submitting the data obtained through sensing current, voltage, and power. It is a bi-directional zero drift current/ power sensing module mainly used in digital multimeters and power profilers.

I suggest you read this post all the way through as I’ll detail the complete Introduction to INA219 covering datasheet, pinout, features, and applications. Let’s get started.

Introduction to INA219

• INA219 is a current/power sensor module mainly employed to sense the power, voltage or current where up to 128 samples can be averaged together to get filtering in noisy environments. This data is then submitted to a microcontroller using the I2C bus.

• This device features an I2C protocol mainly used to transmit data between devices. The I2C protocol comes with two wires SDA and SCL. The SDL is a serial data line that carries the data while SCL is a serial clock line that carries the clock signal and ensures the synchronization of data transfer over an I2C bus.

• In the I2C protocol, one device acts like a master and the other as a slave. Using this communication protocol you can attach multiple slaves with a single master whereas you can also control single or multiple slave devices with multiple masters.
• INA219 can be easily incorporated with microcontrollers and Arduino boards and with devices that come with an I2C bus interface.
• It also contains a 2W 0.1 Ohms 1% rated shunt resistor mainly employed to fulfill the current measuring requirements.
• This sensor module is a key part of the power monitoring systems. The power input of this device ranges from 3V to 5.5V and the target voltage is up to +26V.

INA219 Datasheet

It is better to go through the datasheet of the device before you embed this device into your electrical project. The datasheet features the main characteristics of the module. Click the link below to download the datasheet of INA219.

INA219 Pinout

The following figure shows the pinout diagram of INA219. The following table represents the pin description of each pin incorporated into the module.

Pin Description of INA219
Pin No.	Pin Description	Pin Name
1	Sensed Input line -	VIN-
2	Sensed Input line +	VIN+
3	Input voltage	VCC
4	Connected to ground	GND
5	Serial clock line that carries the clock signal	SCL
6	Serial data line that contains the data	SDA

INA219 Features

• Contains 2C- or SMBus-compatible interface
• Comes with up to +26V target voltage
• Power Input Range = 3.0V-5.5V
• Can Sense Bus Voltages ranging from 0 to 26 V

• Up to 128 samples are averaged to get filtering in noisy environments.
• Capable of up to ±3.2A current measurement, with ±0.8mA resolution
• Contains ohm 1% 2W current sense resistor
• Board Dimension = 0.8 x 0.9 inch (l x w x h)

INA219 Applications

• Used in power monitoring systems
• Employed in power profiler
• Used in digital multimeter

That’s all for today. Hope you find this article helpful. If you’re unsure or have any questions, you can approach me in the section below. I’d love to help you the best way I can. Feel free to share your valuable feedback and suggestions around the content we share so we keep coming back with quality content customized to your exact needs and requirements. Thank you for reading the article.

Introduction to MAX30100

Hello friends, I hope you all are doing great. In today's tutorial, we are gonna have a look at a detailed Introduction to MAX30100. MAX30100 is a heart pulse rate monitor sensor. This sensor consists of two Light Emitting Diodes (LEDs), (one emits infrared light and the other emits red light) modifiable optics, low noise signal processor that detects heart pulse rate signal. Its operating voltage is from 1.8v to 3.3v.

The MAX30100 is used in different industrial and medical equipment such as fitness measurement devices, medical devices, and different wearable instruments. In today's post, we will have a look at its working, pinout, protocol, features, etc. I will also share some links where I have interfaced it with other microcontrollers. If you have any questions about it please ask in the comments, and I will resolve your problems. So, let's get started with a basic Introduction to MAX30100.

Where To Buy?
No.	Components	Distributor	Link To Buy
1	MAX30100	Amazon	Buy Now

Introduction to MAX30100

• MAX30100 is a heart pulse rate monitor sensor. This sensor consists of two Light Emitting Diodes (LEDs), (one emits infrared light and the other emits red light) modifiable optics, low noise signal processor that detects heart pulse rate signal.
• This module can be configured by software registers, and its output data is stored in sixteen FIFOs on this module.
• This sensor communicates with the other microcontroller by the I2C interface. The pulse measurement system in this module has Ambient light cancellation, 16-bit ADC, and a time filter.
• It has an I2C digital interface to communicate with a host microcontroller. MAX30100 has ambient light cancellation, 16-bit ADC and a time filter.
• This module uses low power which makes it useable for battery-operated systems. It operates on the voltage range of 1.8 to 3.3V.
• As earlier we discussed that it has two Light Emitting Diodes, one emits red light with a wavelength of (650nm) and the other emits infrared with a wavelength of (950nm).
• As this device is used for measurement of heart pulse rate and oxygen concentration in blood, for these measurements wear this sensor on your finger or earlobe it can also put any part of the body which is not thick.
• When you wear it on your finger for measurement both infrared and red light pass through the tissues of a finger, absorption these lights can be measured by a photodiode.
•  Depending on the quantity of oxygen which you have in your blood the ratio of absorbed red light and infrared light will be different.
• By this ratio, we can easily calculate the oxygen level in your blood hemoglobin.

• Now we discuss the Pinout of MAX30100.

MAX30100 Pinout

• These are the main pinouts of MAX30100.

Pin#	Type	Parameters
Pin#1, 7, 8, 14	N.C	These pinouts are not used for any purpose. All these are open pinouts.
Pin#2	SCL	This pin is used for I2C clock for input.
Pin#3	SDA	This is I2C bidirectional data sending pinout.
Pin#4	PGND	This is pin is used for power ground of drivers of light emitting diodes.
Pin#5	IR_DRV	This pin is used for cathode of infrared led to connect with the LED drivers point. You can
Pin#6	R_DRV	This pin is for the cathode of red LE to connect with its driver point. This can also be suspended in a circuit.
Pin#9	R_LED+	This pin is for red led to connect with the supply voltage. By this pin, it is connected with the infrared led.
Pin#10	IR_LED+	This pin helps to connect the anode of infrared led to the input voltage. It is connected with the red led by internally.
Pin#11	Vdd	This is input supply pinout for this module, you can connect this with the ground for better performance.
Pin#12	GND	It is an analog Ground pin.
Pin#13	INT	It is Active-Low break off pinout.

For better understanding lets see the pinout diagram.

Features of MAX30100

• These are some features of MAX30100.
  •  This sensor is available in the simplest circuitry for heartbeat measurements.
  • This module consists of two led infrared and red, a photodiode for light sensing, and, has an analog front end.
  • The dimensions of this module are 5.6mm x 2.8mm x 1.2mm with the fourteen pinouts which are available in optically improved closed packages.
  • It provides low power battery solutions for handheld electronic devices. We can program It in an easy way and suitable for low power components.
  • Its high signal to noise ratio (SNR) gives high motion production flexibility.
  • This sensor provides the confined light annulment, higher rate capacity, and fast-moving output data.

    MAX30100 Arduino Interfacing

• Now we discuss its Arduino interfacing by giving an example of a project, which described below. Let's discuss this project with detail.

Project Component

• These are components which we will use for this project.
  • Arduino Nano.
  • Small Breadboard.
  • Wires.
  • The Bluetooth Module HC-06.
  • Sensor MAX30100.
  • Light Emitting Diode (LED).
  • Two resistors of 4.7k Ohm.
• First of all, we connect all these components with each other for working of MAX30100, given diagram shows us a better understanding of connections this circuit.
• First connect all pinouts of MAX30100 with the wires, connect female part of a jumper with sensor and left male part open for Arduino interfacing. For the wiring connection, you can see a given picture.
• After connecting MAX30100 with wires and jumpers we will also connect HC-06 with wires. Let's discuss this process.
• All data received by this Bluetooth device we send to Arduino by serial communication.
• This Bluetooth mode is like the Bluetooth which sends data to ten meters range. The HC-06 works like a slave device, which means it allows other devices to connect to make the connection with it.
• This Bluetooth module has four pinouts which are supply pin (Vcc), ground (GND),  receiver (RX) and transmitter (TX).
• After all these connections we will set all these components on a breadboard and connect them with each other.
• Let's discuss these connections step by step with detail.
• First step:  Connect the Arduino with the breadboard.
• Second step: After interfacing of Arduino on a breadboard, connect the Bluetooth device with Arduino in a given sequence of wires.
  •  TX1 pin of Arduino connects with the Bluetooth pin RX.
  •  Connect RX0 pinout of Arduino with the TX pin of the Bluetooth module.
  • Connect the ground of HC-o6 with the ground Arduino.
  • Connect Vcc pin of Bluetooth with the Arduino 5V pinout.
• Third step: This step we connect MAX30100 with Arduino. Connection discusses incoming lines.
  • Connect Vin pinout of MAX30100 sensor with the Arduino pinout of five volts. (As we did in with the Bluetooth).
  • Connect A5 pinout of Arduino with the SDA pin of the MAX30100.
  • A2 pinout of Arduino connects with the INT pin of MAX30100.
  • Ground pinout of MAX30100 connects with the ground pin of Arduino.
  • After this assemble one resistor in the breadboard and connect one end of the resistor with  5V pinout and another point of the resistor with A5 pinout.
  •  Take another resistor and connect it with the 5v pin and A5 pinout.
• Fourth step: Afterall this interfacing we will connect an led to show reading s of the sensor.
  • First, connect the small point of light emitting diode with the ground pin and connect the other part of the light emitting diode with the D2 pinout.

Applications of MAX30100

• These are some applications of MAX30100.
  • It is used in handheld devices.
  • It is used in devices related to fitness measurement.
  • It use as main componnet in medical measurment devices.

So, that was all about MAX30100, if you want to know something more about it as in comments I will explain to you more about it. Take care until the next tutorial.

Introduction to MPR121

Hello friends, I hope you all are doing great. In today's tutorial, we are gonna have a look at detailed Introduction to MPR121. MPR121 is a touch sensor controller, its working is like the capacitor's working principle. This module has twelve electrodes points, it communicates via I2C protocol. When any objects come closer to an electrode point, we can observe the presence of an object by variation in capacitance of an electrode. It's working voltage should be between 2.5 to 3.6 VDC. MPR121 is used in different industrial projects and electronic devices such as mobile phone and remote control systems. In today's post, we will have a look at its working, pinout, protocol, applications, etc. I will also share some links where I have interfaced it with other microcontrollers. If you have any question about it please ask it in comments I will resolve your problems. So, let's get started with a basic Introduction to MRP121.

Introduction to MPR121

• MPR121 is a touch sensor controller, its working is like the capacitor's working principle. This module has twelve electrodes points, it communicates via I2C protocol.
• This module has the capability to drive LEDs and GPIO on 4 to 11 electrodes pins,  this feature provides freedom to set-up different projects.

• This sensor consumes very low current, it draws only around 29uA current after 16 milliseconds.
• Instead of traditional buttons, this board has four holes which used as an input system.
• The level changer of 3.3v to 5v is surfaced on this chip which provides the facility of 3.3v and 5v I2C interfacing with other microcontrollers.
• On the back side of this module, there are four jumpers which are closed to each other by default.
• The jumper of address pin connects the Add pin to a ground of chip, which indicates that default I2C address of this chip is 0x5A.
• If you want to change the address of the MPR121 chip, first of all, you should open the jumper. Jumpers are also connected with SCL, SDA and interrupt pin.
• The VERG pinout of this module is connected with a ground by a 0.1uF capacitor, which indicates that you can not operate the MPR12 at low supply voltage mode (1.71-2.75VDC) until you modify the board.
•  The dimensions of this module are 3cm x 2cm.

Now, we discuss the pinouts of MPR121.

MPR121 Pinout & Description

There are main twenty pinouts of MPR121 which are described below.

Pin#	Type	Parameters
Pin#1	IRQ	It is Open Collector Interrupt Output Pin, active low.
Pin#2	SCL	It is I2C Clock pinout.
Pin#3	SDA	It is I2C Data pin.
Pin#4	ADDR	It is I2C Address Select Input Pin. Connect the ADDR pin to the VSS, VDD, SDA or SCL line, the resulting I2C addresses are 0x5A, 0x5B, 0x5C and 0x5D respectively.
Pin#5	VREG	It is Internal Regulator Node. Connect a 0.1 µF bypass cap to VSS.
Pin#6	VSS	Ground.
Pin#7	REXT	It is an External Resistor. Connect a 75 kO 1% resistor to VSS to set internal reference current.
Pin#8	ELE0	It is Electrode 0 pinout.
Pin#9	ELE1	It is Electrode 1 pinout
Pin#10	ELE2	It is Electrode 2 pinout.
Pin#11	ELE3	It is Electrode 3 pinout.
Pin#12	ELE4	It is Electrode 4 pinout.
Pin#13	ELE5	It is Electrode 5 pinout.
Pin#14	ELE6	It is Electrode 6 pinout.
Pin#15	ELE7	It is Electrode 7 pinout.
Pin#16	ELE8	It is Electrode 8 pinout.
Pin#17	ELE9	It is Electrode 9 pinout.
Pin#18	ELE10	It is Electrode 10 pinout.
Pin#19	ELE11	It is Electrode 11 pinout.
Pin#20	Vdd	Connect a 0.1 µF bypass cap to VSS.

For further understanding let's see the pinout diagram.

Features of MPR121

• These are some features of MPR121 which are described below.
• Its operating voltage is 1.71V to 3.6V
• Its operating current is 29uA at 16ms sampling interval.
• Its scan stop mode current is 3uA.
• There are twelve electrodes sensing inputs on this module in which 8 are multifunctional for LED driving and GPIO.
• For electrode inputs, it has integrated auto calibration.
• It can configure charge current and charge time for each electrode.
• It's every electrode has separate touch and release trip thresholds, which provides hysteresis and release trip thresholds for each electrode.
• It has an I2C interface, which has IRQ interrupt output to informs electrodes for condition changes.
• The dimensions of 3 mm x 3 mm x 0.65 mm 20  with the lead QFN package.
• It's operating temperature is range is -40°C to +85° C.

  MPR121 Capacitance Measurement & Touching Sensing

• The capacitance measurement part of MPR121 is consists of a sensing electrode pad which is connected with the sensing inputs of MPR121. MPR121 used the I2C bus and interrupt output for communication with the processor of a host device.
•  There are 13 sensing channels, in which 12 channels have physical inputs electrodes and one multiplexer, and the 13th channel is used for proximity detection.
• From a given diagram, we can see that multiplexer is fixed at the front end, due to this all thirteen channel can be measured in sequence within time. After capacitance measurement, this sensor gets filtered noise by which we can observe touch or release button status.
• Except for the measurement of touch sensing, MPR121 is also used in industries for capacitive measurement applications.
• You can send up to ten-bit data ( which indicates a high level of the noise elimination) for capacitance measurement outputs like measurement of water level, displacement measurement, and change of medium content measurement.
• The measurement of capacitance on each channel is the capacitance to the ground which is the sum of background parasitic capacitance to ground (Cb) and a finger touched induced capacitance (Cx).
• The ground is in common ground when the module is not in an active state when the device is connected with batteries this ground is referred to MPR121 ground.
• MPR121 used DC current for measurement of capacitance. For measurement of capacitance every channel first charged and then discharged to ground, this process you can see in a given diagram.
• We can read values of all channels one by one when one channel is charged or discharged, other channels are connected to ground.
• A quantity of charge can be varied by changing the value of current and charge. After charging of electrode, the value of peak voltage can be measured by 10-bit ADC.  These output voltages are inversely proportional to the value of capacitance on all the channels.

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Applications MPR121

• These are some applications of MPR121.
  • It is used in PC Peripherals.
  • It is used in MP3 Players.
  • It is used in Remote Controls.
  • It used in Mobile Phones.
  • It is used for Lighting Controls.

So friends that were all about MPR121, if you have any questions about please ask in comments. Take care until the next tutorial.