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The electrical grid is a part of our infrastructure that we often overlook. It provides the power needed to run our homes, businesses, and critical services shaping the society we live in. Have you ever stopped to think about the history and importance of this network? Let's delve into how it functions, from the energy sources that fuel it to the technological advancements, the challenges it confronts, and what lies ahead.

The Modern Energy Grid is a Very Sturdy System

When was the time you faced a power outage? When your lights flicker, or the power goes out, it's a reminder of how we depend on the grid. Our daily routines are closely connected to its operation powering everything, from our morning coffee makers to equipment in hospitals. Disruptions in the grid can have far-reaching consequences affecting communication networks, transportation systems, and even the economy.

Beyond the individual inconveniences of power outages , the electrical grid plays a crucial role in supporting a well-functioning modern society. Think about how businesses and industries suffer when there's a grid failure. Production slows down, employees cannot perform their duties and all commercial activities grind to a halt. Key infrastructure, like water treatment facilities, hospitals, and emergency services heavily rely on electricity to deliver services to the public.

Exploring Various Energy Sources

Energy serves as a driving force that fuels our society.  In order to meet the ever-growing demand for power, we rely on a variety of energy sources, from simply burning stuff, to converting sunlight into usable power.

Conventional energy sources, like coal and natural gas, have historically been the mainstay of energy production. These sources are known for their reliability in ensuring an electricity supply. They also offer high energy density, allowing them to generate power in a compact space. However, their efficiency levels can vary. For instance, coal-fired plants typically run at 30-40% efficiency, while natural gas turbines and power plants can reach efficiencies of up to 60%. Gas turbines can quickly start up and provide peak power during times of high demand.

Recently, renewable energy sources like solar, wind, and hydroelectric power have become more popular due to their benefits and improved cost-effectiveness. These resources rely on sources that make them sustainable in the long term. However, they do come with limitations. Solar power is dependent on sunlight availability, which changes throughout the day and is influenced by weather conditions. Wind power relies on wind speed and consistency. Although hydroelectric power is effective and reliable, it is constrained by the presence of rivers or dams.

When evaluating energy sources' effectiveness it's crucial to consider the factors that impact their performance. Assessing efficiency involves looking at how energy's converted resources are used, and the overall effectiveness of a system. Each energy source has its pros and cons in terms of efficiency, environmental impact, and cost. To determine the best energy sources for our needs it's important to weigh the advantages and disadvantages of each option and find a balanced approach.

Advancements in Technology

Technological advancements have greatly improved the efficiency and reliability of the electricity grid. Smart grids for instance use sensors, automation, and two-way communication to optimize energy distribution, reduce power usage during peak times, and quickly address any issues that may arise.

Thanks to progress in grid design and control systems, integrating renewable energy sources into the power network has become more viable. Energy storage technologies, such as batteries and pumped hydro, have also emerged as components in recent years, allowing surplus energy to be stored for use when demand is high.

Challenges and Vulnerabilities

Despite the advancements made the power grid is still facing challenges and vulnerabilities that require attention. The issue of an aging infrastructure is significant, given that many parts of the grid were built decades ago which often goes unnoticed. Additionally, the increasing risk of cyberattacks poses a threat to both the reliability and security of the grid. Natural disasters such as hurricanes, floods, and wildfires can also result in damage and disruptions to electricity supply for prolonged periods. To address these issues it is crucial to invest in modernizing the grid while focusing on enhancing its resilience and strengthening cybersecurity measures.

The Future of the Grid

The outlook for the power grid appears quite promising. The trend towards decentralization is becoming more apparent as consumer-level distributed energy generation gains popularity. The move towards electrifying transportation, through the use of electric vehicles, will require an updated grid infrastructure to support charging stations and meet growing demand. Furthermore, the adoption of renewable energy sources will contribute to establishing a friendly and sustainable grid reducing our reliance on fossil fuels.

Role of Consumers and Energy Conservation

While progress in grid technology and energy production is crucial, each of us plays a part in supporting its reliability and sustainability. Simple actions, like being mindful of energy consumption, can have an enormous impact. Practices such as using energy-efficient appliances, turning off lights, and improving building insulation can significantly reduce energy usage. Opting for renewable energy sources, like rooftop solar panels, can also play a role in promoting overall sustainability within the grid.

Final Thoughts

The power grid has changed over time, becoming an integral part of our daily lives. Its reliability is often taken for granted, yet even the smallest disturbances can have far-reaching effects, highlighting its importance in today's world. As we work towards a sustainable future by embracing renewable energy sources and advancements in grid technology, new opportunities arise. However, we must address challenges such as aging infrastructure and cybersecurity threats, with individuals contributing by practicing energy efficiency and conservation.

Let us appreciate and support the electrical grid that powers our lives and be conscious of our energy usage and its impact on this essential infrastructure.

Hello learners! Welcome to the introduction of the round PCBs, where we are going to discuss the round PCBs in detail. This is specially designed for articles for beginners as well as for intermediate skills in printed circuit boards. PCBs are the backbone of any circuit, and it is crucial to understand the type and application of the circuit and its PCB in detail before starting to work on it. 

If you are going to buy crucial products like PCBs, always choose the best option that has positive reviews and a great experience. The best option for this is PCBWay.com, which has a great variety of PCBs, electronic components, equipment, and services. They have a vast variety of PCB services that range from high-speed PCBs to optical module PCBs, semiconductor tests, aerospace PCB circuit boards, and many other fields in different shapes, including round PCBs.

The best thing is that they provide the fastest services, and ordering online is easy here. Go to PCBWay.com and click on the PCB instant quote. They will ask for different parameters that you have to fill according to your circuit. Choose the build time and add it to the cart. You can find the detailed process on their website.

In this article, we’ll see the basic introduction of round PCBs. We’ll see the definition of round PCBs and understand how they are different from the other shapes. After that, we’ll see its manufacturing in detail and will see different phases of manufacturing. We’ll also have a look at their application. Let’s start learning.

Introduction to Round PCB

The PCBs are present in different shapes and sizes and are customized by keeping different parameters in mind such as the scope, type, and working of the circuit. Usually, people have seen rectangular or square PCBs but one must know that round PCBs bring flexibility and functionality in the design and features of the circuits. To easily understand these, let's have a look at their introduction:

"Round PCBs are different from rectangular or square PCBs in terms of shape and applications and these bring factors like space utilization in circuits and provide better performance in different scenarios."

These PCBs introduce signal integrity in the high-frequency circuits because the components are tightly packed in the curved traces and as a result, better performance is gained. The difference is the presence of the curves in the round PCBs that have multiple advantages in the circuits. 

Round PCBs Manufacturing

Just like other PCBs, the manufacturing of the round PCBs involves different steps and special techniques are applied in these steps. Let’s have a look at these steps:

Round PCBs Design and Garber Files

A PCB design software is used to get started with the design process of round PCBs. it creates the schematic and layout of the circuit. In the case of round PCBs, great care and attention are required because of the curves. The route tracing and component placement are different from the rectangular or square PCBs. 

Once the round PCBs are designed, the process of Gerber file generation is carried out. This file has multiple instructions and information regarding the design and some of them are listed below:

• Copper layers
• Solder mask
• Silkscreen
• Drill holes

Round PCB Panel Preparation

The Garber file just discussed is used for the creation process of the photomasks. These are the essential photographic films that have patterns related to the different layers in the round PCBs. A large sheet of laminated material such as the FR4 is cut into the designed panel. A feature of this panel is, that it is pre-drilled with the registration hole so that it may be aligned with the design. 

Round PCB Inner Layer Imaging and Etching

A photosensitive film (photoresist) is put to the copper foil in the laminate panel's inner layers.

The photomasks for these layers expose the required patterns to ultraviolet (UV) light. The exposed photoresist hardens, leaving the unexposed portions soft. The panel is then processed, eliminating any unexposed photoresist. This leaves the copper traces exposed. The visible copper is chemically etched away, leaving the inner layers with the appropriate circuit designs.

Round PCB’s Lamination and Drilling

The design is now get ready with different processes such as the lamination of the surface and then drilling the holes according to the design. If the design consists of different panels then all of these are aligned together to get the best output. Once the panel is ready, the imaging and etching of the outer layer are carried out to create the final product in terms of design.

Platting of the Round PCBs

The PCBs are then passed through the process of platting. Here, a thin layer of the conducting material is applied to the required arrears to provide conductivity. Usually, this layer is copper because of its best-conducting characteristics. 

Round PCB’s Soldermask and Silkscreening Process

Once the copper (or any other material) is traced on the round PCBs, a solder mask is applied to the PCB so that the traces may be protected against oxidation. In the end, the silkscreen is applied to the PCBs to add more details.

Applications of Round PCBs

The applications of the round PCBs are the same as the traditional ones but they play a crucial role in improving factors such as performance and space constraints. Here are some advantages that you must know:

Round PCBs Consumer Electronics

The consumer electrics are changing day by day. Smart technologies have made these electronics smaller and more stylish. The round PCBs help to get better performance in the smaller space. For instance, these are used in smartwatches, fitness trackers, and related wearables where the round shape fits into the device easily. 

Round PCBs in the Medical Devices

The medical devices are becoming smaller and smarter. For instance, the large X-ray machines, or blood pressure measuring devices are smaller now and are used as wearables. The round PCBs are used here because of their round curves and smart shape to fit in these devices. 

Round PCBs in the Automotive Industry

The round PCBs are not only smart but are more appealing in their looks. The automotive industry requires circuits that not only provide better performance but also look more stylish. Some automotive instrument clusters and control panels always prefer round PCBs because of their look.

As a result, we have understood the round PCBs in detail in this article. We started with the introduction to the round PCBs and then saw how these PCBs are designed and ready to work. We saw why these are better in performance and in the end, we discussed how to get the best PCBs from PCBWay.com. I hope all the points are clear now and if you want to know more, you can contact us.

Hey students! Welcome to another episode of the MQ gas sensor series. Today, we are interested to learn about the high-performance sensor that is used to detect the presence of benzene gas. This is the MQ138 gas sensor and it instantly detects the target gas because it has tin dioxide as the sensing element. Usually, it can detect multiple gases and is considered as the Volatile organic compounds (VOC) sensor but the most significant target gas of this sensor is benzene therefore, we’ll pay attention towards the discussion of the benzene detection through this sensor. Many features of this sensor resemble other members of the MQ gas sensor series and we’ll read its basic features and specifications in detail. 

In this article, we’ll initiate the discussion with the basic introduction of this sensor where we’ll also see its basic components and their purpose. After that, we’ll show you the datasheet elements that will be helpful to understand its technical specifications. You will also see the working principle, physical dimensions and applications of this sensor in different fields as well so stay with us.

Let’s start with the first topic:

MQ138 Benzene Gas Sensor Introduction

The MQ138 is a member of the MQ gas sensor series that is specialised for the detection of benzene gas around it. It works on low voltages and uses tin oxide as the sensing element that is readily available to detect any leakage of the benzene gas in the surrounding air. Mainly, it follows the chemiresistor which is defined as:

"The chemiresistor of an element refers to the mechanism in which its electrical resistance changes when it absorbs the surrounding gas."

The sensing element of MQ138 absorbs the target gas and the change in the concentration is indicated through the analogue values of the sensor.

We know that benzene is used in multiple industries as a fuel as well as for chemical reactions but exposure to this gas is hazardous for humans. If accidentally inhaled for a short time, it can cause the issue issues like dizziness, and headaches and long-term inhalation is even more dangerous and can also cause cancer. These are the points that make the presence of benzene gas sensor systems such as with MQ138 compulsory at such places. 

Let’s see the components of this sensor to know its details:

MQ138 Benzene Gas Sensor Ceramic Tube

There is a small ceramic tube-like piece of alumina (AL2O3) that works as the mechanical support to the sensing element. This ceramic tube has excellent thermal stability as well as resistance to the electrical current therefore, this does not cause any change in the electrical resistance of the sensing element but only provides the mechanical strength. This results in the uniform absorption of the target gas on the evenly spread sensing element it. 

MQ138 Benzene Gas Sensor Sensing Element

The heart of the MQ138 is the sensing element that is made of tin oxide (SnO2). This is present evenly on the ceramic tube and ready to react with the benzene gas if gas is leaked into the air. Tin oxide has less conductivity to the clean air as compared to the air mixed with benzene therefore it is used as the sensing element in such sensors. 

MQ138 Benzene Gas Sensor Heating Circuit

The heating sensor plays a crucial role in sensors like MQ138 because it maintains the required temperature to stimulate the optimum performance of the temperature. This consists of a heating coil made of nichrome wire and gradually increases the temperature of the sensing element. This is a crucial process and whenever the sensor is turned on, the heater circuit gets the 5V power and starts its work. 

MQ138 Benzene Gas Sensor Housing and Base

The circuit of the sensor is delicate and requires protection from outward agencies such as dirt particles in the air. This is done by a perforated metallic cap that covers the whole sensor. It acts like a filter that only allows the gas to pass through it and as a result, the system may perform best for a long time.

Moreover, the whole body of the sensor is made with plastic or bakelite material. The sensor modules have a large base that has multiple items on it such as the power LED, pins, etc but the sensor alone has a relatively simpler structure and the base has pins for the direct connection in the circuit. 

MQ138 Benzene Gas Sensor Datasheet

Prior to employing any device, it is essential to review the device's datasheet so we are discussing some crucial points from the datasheet of the MQ138 benzene gas sensor:

MQ138 Benzene Gas Sensor Features

The MQ gas sensor series has simple and fundamental features and I am highlighting the most basic features of the MQ138 sensor from its datasheet:

• It has a wide detecting scope and a quick response time so is a reliable option.
• It provides stable performance and has a long life so is an affordable sensor.
• It shows the analogue values at its analogue pin that allow the user to see the concentration level of the benzene gas.
• It has a digital pin the values of which can be set through the potentiometer.
• This sensor has electrostatic discharge (ESD) protection which is one of the reasons behind its long life.
• It shows the protection against the overvoltage.
• It has a simple drive sensor and requires 20 seconds for the pre-heating.

MQ138 Benzene Gas Sensor Specifications

The table given below shows the specifications of the MQ138 benzene gas sensor:

MQ138 Benzene Gas Sensor Basic Circuit

The labels of the image given above are explained below:

• VCC: This pin connects to the positive terminal of the power supply which is typically 5V.
• GND: This pin connects to the ground terminal of the power supply to complete the circuit.
• H or Heater: This pin connects to one side of the resistor (RL) which is responsible for limiting the current flowing through the sensor's internal heating coil that is mentioned before in this article.
• RL: This is the load resistor in series with the heating coil. The typical value for the MQ-137 is around 10KΩ which may vary according to the model.
• A or B: These pins are interchangeable and connect to the circuit voltage which is typically 5V.
• OUT or Signal: This is the analogue output pin that provides a voltage signal that varies depending on the benzene gas concentration around the sensor.

If you want to learn more about the datasheet of this sensor in detail then you must see the link that is provided here:

MQ138 Benzene Gas Sensor Pinout Configuration

Till now, we have been discussing the pins and their features at many points but for ease of learning, here is a table that shows the pins, their name, and precise descriptions that will help you to understand this sensor’s pin details:

MQ138 Benzene Gas Sensor Packages

MQ138 Benzene Gas Sensor Alternatives

Multiple other options can be used in place of the MQ138 benzene gas sensor. Some important names in this regard are listed below:

• Electrochemical Sensors (Benzene Specific)
• Benzene-Specific Semiconductor Sensors
• Air Quality Sensors (VOC Detection - Might include Benzene)

Where to Buy MQ138 Benzene Gas Sensor

Always buy sensitive devices like M138 from the well-reputed source and some of such examples are given below:

• eBay
• AliExpress
• Amazon

MQ138 Benzene Gas Sensor Working Principle

Just like the simple structure, the MQ138 benzene gas sensor has the simple way to work. As mentioned before, it follows the chemisterisitor and the details of this are shared in the following points:

As soon as the sensor is powered on, the heating circuit starts it work. It requires 20-25 seconds from the preheating and gradually, the temperature of the sensor reaches 300 Celsius.

• At this temperature, the tin oxide is readily available for the reaction and it starts reacting with the surrounding air (assume it is clean air). At this point, the oxygen ions start accumulating on the surface of the sensing element. This results in an increase in the electrical resistance. These values are sent through the analogue pin.

• The sensor is ready to detect any target gas around it.

• When the target gas is leaked into the air, the oxygen ions from the depletion region react with it and start melting. This results in a decrease in the electrical resistance. 

• The change in the electrical resistance is indicated on the analogue pin and sent to any output device. 

• If the threshold value is set through the potentiometer then when the analogue values reach it, the sensor shows the digital output on the digital pin and this results in the indication of this gas on output gas without any need of a microcontroller. 

• The higher the concentration of target gas around the sensor the more is the magnitude of the analogue value. 

MQ138 Benzene Gas Sensor Physical Dimensions

MQ138 Benzene Gas Sensor Applications

• Industrial Leak Detection

• Occupational Safety Monitoring

• Air Quality Monitoring

• Environmental Remediation

• Indoor Air Quality Monitoring (limited)

• Personal Safety Devices (specialized)

Hence, today, we have seen the detailed information about the MQ138 benzene gas sensor. Our exploration commenced with a fundamental introduction, followed by an examination of the essential components comprising this sensor. We also understood the basic points from the datasheet of this sensor and then moved towards the working principle and through the steps, we understood the detail of how it detects the target gas. In the end, we saw the packages, dimensions, and applications of this sensor. I trust that I covered all the points and if you want to know more, you can ask in the comment section.

Hi readers! Welcome to the next article on the MQ series gas sensors. Today, our motto is to learn about the basic information of the MQ137 ammonia gas sensor. We know that ammonia gas is extensively used in industries, agricultural lands, Environmental Monitoring, Health and Public Safety, etc. In such areas, there are great chances of leakage that can be harmful and here, sensors like MQ137 are used for the instant detection of the Ammonia gas. It is a colorless gas with a distinct pungent smell and its inhalation may cause eyes, lungs, nose, and throat infections and irritation. So, the MQ137 is specialized for its detection and acts as a life savior in such cases. 

In this article, we’ll commence our discussion with the basic introduction of the MQ137 ammonia gas sensor and will learn its basic structure to understand its features. After that, we’ll see some important points from its datasheet such as its specifications and some important graphs related to its performance. We’ll shed light on its working principle and physical dimensions and in the end, you will see the basic fields where this sensor is widely used. Let’s move towards the first point:

MQ137 Ammonia Gas Sensor Introduction

The MQ137 is an ammonia gas sensor designed to detect ammonia gas in various environments. This is available either as a module or as a sensor and can be integrated into appropriate electronic circuits or microcontrollers such as Arduino, ESP32, etc. The module comes with digital and analog pins and here, the digital pin makes it operate even without using the microcontroller with it. 

Ammonia is a hazardous gas for human inhalation and it causes multiple health issues even with minimal exposure. The MQ137 has the sensing element that instantly reacts with the ammonia gas and changes in the analog pin values indicate the concentration of ammonia around the sensor. 

MQ137 Ammonia Gas Sensor Basic Components

The internal structure and components of the MQ136 ammonia gas sensor are similar to other members of the MQ gas sensor series. Here is the list and a little description of each of them:

MQ137 Ammonia Gas Sensor Ceramic Tube

There is a small tube-like structured piece of ceramic material (micro AL2O3) placed on the circuit of the MQ137 ammonia gas sensor. The reason behind choosing AL2O3 is its excellent thermal stability. Moreover, it does not affect the electrical resistivity of the sensing element, and, therefore, does not cause any change in the results. 

This ceramic tube provides mechanical strength to the sensing element layer so provides a uniform reacting area to the target gas. This is crucial for the exact analogue values. 

MQ137 Ammonia Gas Sensor Sensing Element

The MQ137 has the tin oxide (SnO2) for the sensing of a target gas. Here, the sensing element is present in the form of a uniform layer on the ceramic tube as mentioned in the previous point. As a result, the mechanical support helps the tin oxide to be readily available for reaction even at a small concentration of ammonia gas. 

MQ137 Ammonia Gas Sensor Heating Circuit

The heating sensor is responsible for maintaining the sensing element’s temperature. It consists of a nichrome wire coil that heats the circuit continuously at a uniform temperature. This small coil is embedded near the sensing element and ceramic tube.

MQ137 Ammonia Gas Sensor Electrodes

The connection between the sensing layer and ceramic material is made with the electrodes made of usually gold (Au). These are responsible for providing the path for the electrical current to pass through the sensing element. These play a crucial role because the measurement of the sensing element resistance is the main principle of this sensor. 

MQ137 Ammonia Gas Sensor Housing and Base

The whole circuit is protected by the firm base and housing. The housing is made of a perforated metal cover that only allows the gas to pass through it therefore, it filters the unwanted particles to reach the delicate internal circuit.

The connection of these pins will be discussed in the coming sections. The module of M137 uses a strong base made of plastic or bakelite that not only provides strength to the circuit but is provides space for the pins. Some modules have an LED that shows the presence of the gas if detected.

MQ137 Ammonia Gas Sensor Datasheet

The datasheet is a crucial document to learn before using any electrical device like the MQ137 ammonia gas sensor. Here are some key sections of the MQ137 sensor datasheet that serve as valuable resources to enhance your understanding and facilitate informed usage:

MQ137 Ammonia Gas Sensor Features

• It has high sensitivity and, therefore, can detect the presence of ammonia gas even at low concentrations. 

• It shows the analog values for the change in the concentration of the gas which helps represent the exact concentration value of the ammonia gas. 

• The presence of the digital output pin makes it useable even without the integration of the microcontroller. 

• The circuit is designed in such a way that it represents a stable output and reliable performance as compared to many other sensors. 

• The wide range of gas detection allows this sensor to provide versatility in the values and detect the gas at a distance as well. It has a fast response time that makes it more reliable. 

• It has easy integration and is present in the form of different packages to make it usable in different circuits. 

MQ137 Ammonia Gas Sensor Specifications

The table given below has all the important specifications that you must know:

MQ137 Ammonia Gas Sensor Circuit Diagram

As mentioned before, the circuit and structure of this sensor are straightforward. Here is a basic circuit diagram that will help you to understand its structure:

The explanation of each label is given here:

• Vc: Loop Voltage (typically ≤ 24V DC)

• VH: Heater Voltage (typically 5.0V ± 0.1V AC or DC)

• RL: Load Resistance (which is adjustable by VR1)

• VR1: Variable Resistor (which is used to adjust RL)

• PH: Heater Consumption (typically ≤ 900 mW)

• RH: Heater Resistance (at room temperature, typically 29Ω ± 3Ω)

• △Vs: Output Voltage (difference between voltage in air and voltage in 50ppm NH3, typically ≥ 0.5V)

• α: Concentration Slope (ratio of resistance at 200ppm NH3 to resistance at 50ppm NH3, typically ≤ 0.6)

If you want to learn more about the datasheet, you must visit the link given below:

MQ137 Ammonia Gas Sensor Pinout Configuration

Till now, we’ve been discussing the pin functions of this sensor but have a look at the table below to understand the pinout configuration with a precise description:

MQ137 Ammonia Gas Sensor Packages

There are no standardized packages for the MQ137 ammonia gas sensor but it is present in more than one variety of assembly options so that it may fit in multiple types of circuits without any issue. Here are key package options widely utilized by multiple users:

MQ137 Bare Sensor Board

It is the fundamental form of the sensor which is a simpler assembly option. It consists of just the sensor and its pins for easy connection. 

MQ137 Sensor Board with Breakout Pins

It consists of the sensor board along with the additional header pins. These pins are soldered on it and provide the opportunity to connect it with the wires or the breadboard according to the convenience of the user. 

MQ137 Pre-Assembled Module

This is the most user-friendly item on the list and the following features will justify my statement:

• It includes the basic board and the additional circuitry like resistors, capacitors, and voltage regulators. 

• Some models have a pre-program microcontroller as well as an analog-to-digital converter (ADC). Such models are ready to use in the projects. Such models come in a plastic enclosure and have features like screw terminals or header pins for easy connection. 

MQ137 Ammonia Gas Sensor Alternatives

If for some reason, you want to know the alternatives that can be used in place of MQ137 then I would suggest the following sensors:

• Figaro Figaro H2S-B4 (can be adapted for NH3)

• City Technology Corporation (CTC) T8320

• Alphasense NH3-FS-400

• Gas Sensing Solutions GSS-NH3

• Mettler Toledo InPro 5000 NH3

• Teledyne API TDL-4000

Where to Buy MQ137 Ammonia Gas Sensor?

The sensors are small delicate devices and one must always choose the best platform to buy such products. Here are the most popular names in this regard:

• AliExpress

• eBay

• Amazon

MQ137 Ammonia Gas Sensor Working Principle

The study of the simple structure of this sensor aforementioned helps us to understand its working principle in just a few steps:

• As soon as the sensor is powered on, the coil of the heater circuit starts its work and the temperature of the circuit keeps increasing gradually. Usually, the pre-heating takes 20 to 30 seconds.

• Once the temperature reaches 300 Celsius, the heating temperature works only on the maintenance of the temperature instead of raising it. 

• At this temperature, the sensing element, tin oxide connected with the heating circuit through electrodes is stimulated to absorb the oxygen from the surrounding air. This reaction creates the depletion region of the oxygen ions around the sensing element. This accumulation results in an increased value of the electrical resistance. 

• The sensor works in this condition and is readily available to detect the ammonia gas. 

• Once the ammonia gas is leaked into the surroundings, the depletion region (oxygen ions) reacts with the ammonia which results in the absorption of the depletion layer. The values of the current flow are continuously indicated on the analogue pin.  

• The absorption of the depletion layer results in lower resistance. These values are indicated on the analogue pin output and show the presence of the ammonia gas. The higher values mean more concentration of the target gas in the surroundings and vice versa. 

• The digital pin is utilised to get the signal if the analogue value exceeds the threshold limit. In this way, the sensor even does not require an external microcontroller for the basic functions. 

MQ137 Ammonia Gas Sensor Physical Dimensions

There are different assembly options for the MQ137 sensor but generally, I’ve created the table that has the physical dimensions of the sensor (additional components not included):

The size may vary in different models but these are the generalized values. 

MQ137 Ammonia Gas Sensor Applications

In every place where ammonia gas is either utilized as fuel or any other process, the ammonia gas sensor is an important device. Here are some general applications where MQ137 is widely used:

• Domestic Ammonia Gas Alarm
• Air Quality Monitoring
• Industrial Ammonia Gas Leakage Alarm
• Wastewater Treatment Facilities
• Food and Beverage Industry
• Chemical Industry

Hence, today we have learned a lot about the MQ137 ammonia gas sensor. We commence the discussion with the basic introduction of the MQ137  sensor where we also saw its basic structure and components. After that, we saw the features and specifications from the datasheet of this sensor. We also read about the basic principle of working and the physical dimensions of the sensor. In the end, we saw the names of the applications where the MQ137 is used. I hope this was an informative study for you.

Hi friends! Welcome to another article in which we are highlighting the basic details of a gas sensor from the MQ sensor series. Today, our focus is on the MQ136 hydrogen sulfide gas sensor that instantly detects the presence of the sulfide gas and sends the signals through digital and analog pins to the output devices for timely indication.

Our mission is to understand the basic introduction of this sensor, so we’ll go through it and see the main points of its datasheet, such as its features and specifications. After that, we'll move towards the working principle and physical dimensions of MQ136, and consequently, there will be a discussion of the basic applications where this sensor is widely used. I am sure it is going to be a useful study for you, so let’s get started.

MQ136 Hydrogen Sulfide Gas Sensor Introduction

The MQ gas sensor series is popular for its instant detection of the target gases and their simple structure. The MQ136 is designed for the early detection of hydrogen sulfide gas even at low concentrations. We know that hydrogen sulfide is a colorless gas that has a pungent rotten egg odor and it causes multiple health issues. It is extremely dangerous and potentially, life-threatening if inhaled for a long time. Some immediate side effects of this gas are eye and nose irritation, headaches, dizziness, nausea, and vomiting therefore, it is important to detect the gas leakage at its early stage. 

The MQ136 hydrogen sulfide gas sensor is a widely used detector that has a sensing element made of tin oxide (SnO2) that absorbs the hydrogen sulfide and the change in its electrical conductance provides information about the presence and magnitude of the target gas. 

This sensor is interfaceable with different microcontrollers such as Arduino UNO, ESP32, and NodeMCU to allow communication over various mediums.

MQ136 Hydrogen sulfide Gas Sensor Basic Structure

The provided details below aim to provide insights into the fundamental components of this sensor, aiding in a better comprehension of its overall functionality and facilitating the understanding of additional information:

MQ136 Hydrogen sulfide Gas Sensor Ceramic Tube

The most basic element in the MQ136 is its ceramic tube structure. It acts as the base for the sensing element and because of its physical properties, it does not disturb the electrical resistance of the sensing element. It is present in the form of a small tube-shaped piece usually made of alumina (AL2O3) and it has excellent thermal stability.

MQ136 Hydrogen Sulfide Gas Sensor Sensing Element

The sensing element is the heart of MQ136 because the analogue values of this sensor depend on the electrical resistance of the sensing element. Here, the sensing element is a tin oxide (SnO2) which instantly reacts with gases like hydrogen sulfide gas and this is the basic way to detect its presence. It is present in the form of a thin layer on the ceramic tube and requires preheating time to be ready to react with the target gas.

MQ136 Hydrogen Sulfide Gas Sensor Heating Circuit

This sensor has a heating circuit that maintains the temperature of the sensing element at a certain level. This circuit has the following components:

• Heater Element Resistor: This resistor is integrated within the sensing element itself and its electrical resistance is responsible for generating the heat when the electrical current passes through the sensing element. 

• Series Resistor: Another resistor is connected in series with the sensing element that is mentioned as the series resistor here. The temperature control depends on the resistance value of this resistor. It performs two actions:

• Limits the current flow

• Controls the temperature of the sensing element

• Power Supply: The resistors connect the sensing element with the power supply of the circuit. This has a 5V value and it provides the necessary voltage to the sensing element. 

MQ136 Hydrogen Sulfide Gas Sensor Housing

The MQ136, just like other members of this series, has a metallic cap with ventilation holes on the sensor’s body that covers all the aforementioned components including the sensing element I’ve mentioned before. It performs two operations:

• Acts as a filter to provide the protection of the internal circuit from unwanted particles and allows only the as to pass through it

• Completes the sensor body structure and provides mechanical support

The other details of the structure depend on the type of sensor’s package and that will be discussed in detail in the next sections.

MQ136 Hydrogen sulfide Gas Sensor Datasheet

The datasheets of the product provide official and reliable information from the manufacturer that is crucial to know before using any device. Here are some important points from the datasheet of MQ136 that will help you understand the core information about this sensor:

 MQ136 Hydrogen sulfide Gas Sensor Features 

• It has a dual signal output that includes the analogue and TTL level output (digital output)

• Its TTL output signal is low if the value of the gas concentration is below the threshold value otherwise it is high. 

• It uses the LM393 IC as the main chip that acts as the comparator in the circuit and is helpful in comparing and presenting the digital and analogue values.  

• It has ESD protection. One must know that Electrostatic Discharge (ESD) is the sudden transfer of the electrical charge within the circuit that can damage it but in MQ136, the ESD protection is responsible for the health of the electrical compoeents even at high charge transfer. 

• It has diodes (such as the zener diode) for over-voltage protection so that the circuit may have a long life. 

• It has a simple structure and is easy to use.

• It is present in different packages at cheaper rates. 

MQ136 Hydrogen sulfide Gas Sensor Specification

MQ136 Hydrogen Sulfide Gas Sensor Basic Structure

Some points about the basic structure of MQ136 are aforementioned in the features but the diagram given below will justify the basic structure pictorically:

MQ136 Hydrogen sulfide Gas Sensor Temperature/Humidity Sensitivity

The performance and efficiency of the sensor may vary with some parameters such as the temperature or the humidity level in the air around it. To explain the difference, I am sharing the graph for the humidity and temperature sensitivity diagram with you. Keep in mind, that the temperature and humidity are inversely proportional to each other:

Here, 

Rs =  Resistance of the sensor in 50ppm H2S gas under different temperature and humidity levels. 

Rso = Resistance of the sensor in 50ppm H2S gas under 20℃/55%RH.

If you want to know more details about the MQ136 sensor, be sure to explore the following link:

MQ136 Hydrogen sulfide Gas Sensor Pinout Configuration

The MQ136 sulfide gas sensor comes in different packages and the pinout configuration of these packages is different. Here is the general table of pinout configuration that explains the names and roles of each pin briefly:

MQ136 Hydrogen sulfide Gas Sensor Packages

As mentioned before, the MQ136 is available in different packages and the table given below will show you the features of these packages with their names:

MQ136 Hydrogen sulfide Gas Sensor Alternatives

The MQ136 has a high sensitivity with hydrogen sulfide gas but there are some other alternatives that can be used in place of this sensor and provide the best performance. Here are some alternatives of this sensor:

• Figaro Figaro H2S-B4

• City Technology Corporation (CTC) T8310

• Alphasense H2S-FS-400

• Figaro TGS822

• Sensirion SHT11

• AMS SCS SCD30

• Gas Sensing Solutions GSS-H2S

• Mettler Toledo InPro 5000 H2S

• Teledyne API TDL-4000

Where to Buy MQ136 Hydrogen sulfide Gas Sensor

Before making a purchase decision for a sensitive device like the MQ136, it's crucial to explore various platforms and thoroughly assess both price and quality. The following platforms are recommended for acquiring the MQ136:

• AliExpress

• eBay

• Amazon

MQ136 Hydrogen sulfide Gas Sensor Working Principle

Similar to its fundamental structure, the operational principle of the MQ136 hydrogen sulfide gas sensor is straightforward. The following steps outline its working mechanism:

MQ136 Hydrogen sulfide Gas Sensor Physical Dimensions

The general dimensions of the MQ136 hydrogen sulfide gas sensor are mentioned in the table below:

MQ136 Hydrogen sulfide Gas Sensor Applications

The hydrogen sulfide gas is less commonly used for domestic use but it has the scope at industrial levels. The list below shows the names of applications in which the MQ136 is widely used:

• Domestic H2S gas alarm

• Industrial H2S gas leakage alarm

• Portable H2S gas detector

• Domestic H2S gas alarm

• Industrial H2S gas leakage alarm

• Portable H2S gas detector

• Wastewater treatment facilities

• Air quality monitoring

• Landfill gas monitoring 

I hope I’ve covered all the points in this article. I started with the basic introduction of the MQ136 and saw the details of its basic structure. I also shed light on the datasheet of this sensor and then moved towards the working principle, physical dimensions and applications of this sensor. If you are interested in learning more, you can ask in the comment section.

Hello students! I hope you are doing great. Today, I am going to share a reliable sensor that is widely used to sense the air quality in different types of projects and circuits. The increasing ratio of pollution in the air is alarming, and air quality monitoring systems are the need of the time. The MQ135 can detect and measure a wide range of gases around it and present the output in the form of digital or analogue values.

In this article, we will commence by providing a fundamental introduction to this sensor, outlining the target gases it is designed to detect. Following that, an exploration of the data sheet will be done through its essential elements, incorporating features, specifications, and other basic information. Subsequently, a detailed description of the sensor's working principle and physical dimensions will be presented to facilitate a comprehensive understanding. Finally, the article will conclude by moving towards the various applications where this sensor finds widespread usage. Let's embark on our discussion, beginning with the initial point:

MQ135 Air Quality Sensor Introduction

The MQ132 air quality sensor belongs to the MQ gas sensor series, and this does not stick to a single gas but can detect multiple gases at a time, thus contributing to detecting the overall air quality. It operates on 5V and has the feature to set the threshold value, so whenever the air pollutant crosses a certain limit, it sends the signal to its digital pin, which can be used to set the alarm. Moreover, the continuous signal of the air quality values is sent to the analogue pin.

Unlike many other sensors from the MQ series, it is sensitive to multiple gases, and these are mentioned below:

• Ammonia (NH3)

• Sulfur (S)

• Benzene (C6H6)

• CO2

• NOx

• Smoke

The list does not end here; many other harmful gases are detected with this sensor that may cause issues like lung disease, eye infections, and others, but timely detection of these gases can save lives.

MQ135 Air Quality Sensor Datasheet

A datasheet for any device holds beneficial information and is a prerequisite before choosing any device. I’ve collected some important information from the datasheet that is given below:

MQ135 Air Quality Sensor Features

• It is highly sensitive to a large number of toxic gases that are more likely to be mixed in the air. Some examples are NH3, NOx, CO2, benzene, smoke, etc., which are common air pollutants. 

• It is a small sensor, and the design is simple, therefore, it is less expensive. 

• It is a low-power sensor. 

• Some modules have a power LED that indicates the power mode.

• It is an easy-to-use sensor. 

MQ135 Air Quality Sensor Specifications

The following table will justify the general specifications of this sensor:

MQ135 Air Quality Sensor Basic Structure

As mentioned in the features, the MQ135 has a simple structure that makes it an ideal choice for different types of projects. Here is the basic circuit diagram that justifies this statement:

Here,

RH= The resistor that provides heat to the circuit. 

RL = The load resistor that is connected in series with the circuit. It limits the current flowing through the circuit. 

Vc = It is one of the voltage sources, and this label indicates the DC voltage. 

VH= it is another source voltage but this can be either AC or DC.

MQ135 Air Quality Sensor Sensitivity Curve

The MQ135 can detect multiple gases, but the sensitivity of these gases is not identical. This depends on the speed of the chemical reaction taking place with the sensing element. Based on multiple experiments, experts have designed the following sensitivity curve graph for users:

The above graph shows the sensitivity of the hydrogen, ammonia, toluene, and fresh air by keeping other parameters constant.

MQ135 Air Quality Sensor Temperature/Humidity Characteristics

The external parameters of the sensor affect its working and it shows a slightly different behaviour. Here is the diagram that shows the performance graph of the MQ135 air quality sensor at varying humidity and temperature:

The different lines show the performance of the sensor for the same gas at different humidity and temperature levels in the air.

If you want to know more details about the MQ135 sensor datasheet, you must visit the following link:

MQ135 Air Quality Sensor Pinout Configuration

Based on its structure, I’ve created the table that explains the pinout configuration of MQ135, which is given below:

The pinout may be slightly vary depending on the model of the sensor.

MQ135 Air Quality Sensor Packages

The MQ series is present in different packages for the convenience of the user. Here is a small description that shows the available packages for MQ135 and their features:

MQ135 Air Quality Sensor Alternatives

The MQ series has multiple sensors that can detect the same gases as the QM135 does, but the difference is, that the MQ135 can detect multiple gases at a time. Other members of the series can be used as an alternative to MQ135; if you want to learn about other sensor series that can be used in place of MQ135, here are some options for you:

Where to Buy ABC MQ135 Air Quality Sensor

It is important to buy sensitive devices like the MQ135 from a reliable source. For this, we have created a list of the platforms to buy the best devices, including the MQ135:

• eBay

• AliExpress

• Amazon

MQ135 Air Quality Sensor Working Principle

The simple structure of MQ135 is responsible for its ease of use and great performance. The working principle of this sensor can be understood with the help of the following steps:

MQ135 Air Quality Sensor Pre-heating

As soon as the sensor is turned on, it has to be preheated. This is done with the heating circuit of the sensor. It takes 20-30 seconds to reach a temperature of 300°C. Once this temperature is gained, it works on maintaining this temperature as long as it has the power. 

MQ135 Air Quality Sensor Sensitivity Layer

The heating mechanism stimulates the sensing element to absorb the oxygen from the air surrounding it. The sensing element is made with tin dioxide that, when it absorbs the oxygen, has a sensing layer on its surface.  This happens only for a certain limit because the accumulation of atoms on the surface creates a layer around it. This is the reason why tin oxide has a high electrical resistance in pure air. At this level, the sensing layer has limited availability of free electrons to react with the external pure air.

MQ135 Air Quality Sensor Gas Interaction

Whenever the target gas (smoke or ammonia) is present in the air, the gas molecules are absorbed by the atoms of the sensing element, and this reaction results in the absorption of this layer. As a result, the electrical conductance of the sensing element increases, and these values are indicated through the analogue data at the analogue pin. 

MQ135 Air Quality Sensor Output

The greater the target gas concentration in the surrounding area, the greater the analogue values. The whole circuit is designed in such a way that the analogue pins send the data to the output device for the indication of this change. 

Some models of the MQ135 have a digital pin that shows the presence of gas only when values reach the pre-set threshold limit. The digital pin then sends the signal to the output device. 

MQ135 Air Quality Sensor Physical Dimensions

The physical dimensions of this sensor may vary from package to package but I’ve created a table for you that generally describes it:

MQ135 Air Quality Sensor Applications

Because of its multiple gas detection capabilities, this sensor can be utilized in multiple types of projects. The general list of some important and commonly used terms is given below:

• Domestic gas leak detection

• Indoor air quality monitoring

• Industrial air quality monitoring

• Smart home appliances (air purifiers, ventilation systems)

• Portable air quality detectors

• Automotive applications (emissions, in-cabin air quality)

I hope I have covered all the points that you were searching for. I started with the basic introduction and then moved forward with the datasheet elements of this sensor. We also saw the features, specifications, and working principle in detail and in the end, we say the physical dimension and its applications in different fields of life. I hope it was helpful for you and if you ant to ask more, you can contact us in the comment section.

Hi peeps! Welcome to another tutorial where we are discussing the MQ sensor elements. Today, our focus is on the MQ131 ozone gas sensor. Ozone is a major component of air pollution and it leads to multiple health problems related to the respiratory system and other issues. It also has an adverse effect on the plants and agricultural lands. It is a pungent gas with a pale blue color and usually, it is present in very low concentrations in the normal air. The MQ131 ozone gas sensor is used in outdoor monitoring stations, industries that use ozone for experimentation, laboratories, and sensitive areas that have a high concentration of ozone gas in the environment.

In this article, we’ll study the MQ131 ozone gas sensor in detail. We’ll kick off the discussion with the introduction of this sensor. After that, we'll unveil the datasheet of this sensor where you will see the features and specifications of this product. After that, you will see the working principle and other details followed by an exploration of this product's dimensions and applications.

MQ131 Ozone Gas Sensor Introduction

The MQ131 is specially designed to detect the presence of ozone gas concentration. We know that Ozone is an allotrope of oxygen gas made with three atoms and is indicated as O3. The core component of this sensor is the tin dioxide that can react with the ozone gas therefore, with the specialized structure, it can detect the presence of this gas in the environment.

This sensor has a lower conductivity in fresh air whereas, a high conductivity when the ozone gas is present in the surrounding air. Let’s find out the basic components of this sensor:

MQ131 Ozone Gas Sensor Ceramic Tube

There is a small cylindrical shaped tube made of alumina (AL2O3) that forms the sensor base. It has excellent thermal stability and great electrical resistance. The role of this tube in the sensor is to perform two functions:

1. It provides mechanical strength to the sensing element.
2. It provides the insulating base for the other components of the perfect performance.

MQ131 Ozone Gas Sensor Sensing Layer

Unlike many other members of the MQ series that have tin oxide as the sensing element, the MQ131 ozone gas sensor has Tungsten Oxide (WO3). It is present in the form of a thin layer around the ceramic tube. This structure acts as the heart of the whole sensor because  Tungsten Oxide (WO3) is a metal oxide therefore, its conductivity lies between the conductors and insulators. The MQ131 works on the chemiresistor principle that is defined as:

"The chemiresistor principle refers to the sensing mechanism of an element in which the electrical resistance of the element changes when it absorbs a particular gas or any other material."

This will be more clear when we’ll learn the working principle of this sensor.  

MQ131 Ozone Gas Sensor Electrodes

There are measuring electrodes made of metals like gold (Au) that connect the sensing element with the ceramic tube. It creates a contact between these two and allows the current to pass through the sensing element. These are also responsible for allowing the circuit to measure the electrical resistance instantly. 

MQ131 Ozone Gas Sensor Heater Circuit

A heater circuit is required to allow the tungsten oxide to absorb the gases. This circuit consists of a coil made of nichrome wire. This coil is embedded near the sensing layer and maintains the sensor temperature at 300°C. This temperature is crucial for the reaction between gases and the sensing element. 

MQ131 Ozone Gas Sensor Housing

The whole structure mentioned before is placed and protected on a strong housing. It is enclosed in plastic or bakelite material that performs the following operations:

• It provides a strong base to the circuit so that it may act as a complete device. 

• It allows the gases to pass over it and renders the other particles or substances so that the internal structure is not disturbed. 

• It provides the connection and completes the device so it may be used in different circuits. 

Other MQ series members such as MQ-3, MQ-2, etc have a metallic mesh-like structure for the same purpose but in MQ131, most of the models have the plastic housing and only some of them have the metallic structure.

In addition to these, other elements are present in the basic structure such as the pins of the MQ131 ozone gas sensor and we’ll discuss these in detail in the datasheet. 

MQ131 Ozone Gas Sensor Datasheet

A datasheet is considered an important repository for the devices such as the MQ131 ozone gas sensor and it is always advisable to learn the datasheet before utilising any device in the circuits. Here are the important pieces of information from the MQ131 sensor. 

MQ131 Ozone Gas Sensor Features

• The MQ131 is a highly sensitive device and provides the best sensitivity to the ozone gas O3 over a large range. As a result, it detects even a low concentration of the target gas.

• It operates on very low power and, therefore, is a suitable device to be used in the Internet of Things (IoT) and other projects. 

• It is a cost-effective option for multiple types of projects.

• It shows the analogue and digital output pins where the analogue pin shows the continuous change in the gas concentration and the digital pin shows a binary signal based on pre-set threshold values. 

• It has a compact size design that makes it suitable for almost all types of circuits. 

MQ131 Ozone Gas Sensor Specifications

The following table outlines the key specifications of this high-performance ozone sensor:

MQ131 Ozone Gas Sensor’s Sensitivity Curve

To measure the performance of MQ131, a comparison between its sensitivity curve in fresh air and the one in the presence of ozone gas is useful. Here is the graph that shows both these curves:

Here,

Ro= Resistance of MQ131 sensor in the clean air

Rs= Resistance of MQ131 sensor in the air with ozone gas 

Ro/Rs= Ratio of the MQ131 sensor performance in polluted air to the clean air

MQ131 Ozone Gas Sensor’s Performance Factors

Just like other devices, the MQ131 does not perform ideally in all severe conditions. Factors like humidity and temperature affect the performance and the graph given below will explain the difference:

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

MQ131 Ozone Gas Sensor Pinout Configuration

The MQ131 has four pins in most of its models and in some models, it has additional pins such as a heater and is not connected (NC). Here is the table that shows the description of each basic pin:

MQ131 Ozone Gas Sensor Packages

For the convenience of the user, the MQ131 sensor is present in the form of different packages. A small description of each package is given next:

MQ131 Ozone Gas Sensor Alternatives

Just like the MQ131, there are some other sensors that are created to detect the ozone gas concentration in the air. Some of these are:

• Figaro TGS series gas sensors (e.g., TGS2600, TGS2602)

• Winsen ZE08-O3 Ozone Gas Sensor Module

• SPEC Sensors O3 Ozone Gas Sensor

• Figaro TGS series gas sensors (e.g., TGS4161, TGS4161-E00)

Where to Buy MQ131 Ozone Gas Sensor

Always choose a trusted source to buy sensitive devices like MQ131. Here are the reliable options for you from where you can get different types of products and devices without any difficulty:

• eBay

• Amazon

• AliExpress

MQ131 Ozone Gas Sensor Working Principle

• The structure of this sensor is designed for uncomplicated working and effective results. Here are the steps that are involved in the working principle:

• The heater circuit heats the sensing element at the temperature of 300C and maintains it. 

• The continuous heating stimulates the sensing element to absorb the gases at a high rate. 

• When the ozone gas is present around the sensor, the surface of the sensing element absorbs the ozone molecules.

• The adsorption affects the electrical conductance of the sensing element. This change is sensed through the sensor. 

• The higher concentration of the ozone layer means a great change in the analogue values of the sensor that are indicated through the signals at the analogue pin.

• If the threshold value is set for the sensor, then on a certain limit, the digital signal at the digital pin is shown. 

• These signals are sent to the output devices for further processing.  

MQ131 Ozone Gas Sensor Logic Diagram

The MQ series features a straightforward design, and here is a diagram illustrating its internal structure:

MQ131 Ozone Gas Sensor Physical Dimensions

The MQ131 is available in multiple packages and models but usually, the general dimensions are considered so I’ve created a table with the standard size and dimensions of the MQ131 ozone gas sensor:

MQ131 Ozone Gas Sensor Applications

Ozone is not extensively present gas or is not used as a fuel therefore, it is not present in the common areas just like methane, butane, and other such gases. But, it has different kinds of applications that are used in the specialized departments. Here are some domains where the MQ131 ozone gas sensor is widely used:

• Domestic Ozone Air Purifiers:

It monitors ozone levels produced by air purifiers.

• Industrial Ozone Monitoring

 It tracks racks of ozone levels in various industrial processes here.

• Portable Ozone Detectors

It is used by personnel working in environments with potential ozone risks.

• Air Quality Monitoring

It detects ozone levels in ambient air.

• Environmental Monitoring

It monitors ozone levels in specific locations.

• Educational Experiments

It is used in educational settings to learn about gas sensing principles.

• DIY Projects

It is used in various DIY projects requiring basic ozone detection.

• Home Automation Systems

It integrates with smart home systems for automated ozone monitoring and control.

Hence in this way, we have understood the basic and fundamental concepts of the MQ131 ozone gas sensor. We commenced with the introduction of this gas sensor and then we saw some points of the datasheet such as the features, specifications, and some graphs. After that, we saw the working principle of this sensor and moved forward with the physical dimensions and application of this sensor. I hope all the things are clear to you but if you want to know more about this sensor then you can ask in the comment section.

Metalworking, a craft embedded in the core of human civilization, has played an important role in shaping our history and technological advancements. From the ancient artisans who meticulously forged metal objects to the modern engineers pushing the boundaries of materials science, the art of metalworking has stood the test of time. Let’s explore this intricate craft, tracing its evolution from ancient times to the cutting-edge innovations of the modern era.

A Glimpse into Metalworking's Illustrious Past

The tale of metalworking begins in the annals of ancient civilizations such as Mesopotamia, Egypt and China, where skilled craftsmen honed their techniques to manipulate metals for tools, weapons and adornments. Through hammering, casting and forging, these early metalworkers laid the foundation for the intricate art forms that would endure for centuries to come.

As time moved on, metalworking techniques advanced through the Middle Ages and Renaissance, with the formation of guilds and apprenticeships propelling the craft to new heights of sophistication.

The Industrial Revolution heralded a new era for metalworking, as mechanized processes and mass production revolutionized the industry. The clang of machinery replaced the rhythmic beats of the blacksmith's forge, ushering in an age of innovation and efficiency that would transform the way we interact with metal forever.

Forging the Way Forward

The art of forging, a process that involves shaping metal through hammering and pressing, has been a cornerstone of metalworking since antiquity. From ancient civilizations to modern industrial applications, forging has stood the test of time as a versatile and enduring technique.

In the heart of ancient forges, skilled craftsmen wielded their hammers to shape metal into intricate forms, a tradition that continues to this day in industries such as blacksmithing , automotive manufacturing and aerospace. The alchemy of fire and steel persists in the hands of contemporary artisans, breathing life into metal with each strike of the hammer.

Casting Shadows of the Past

Casting, the art of crafting with molten metal, traces its origins back to the ancient civilizations that first mastered the technique of pouring molten metal into molds. From jewelry making to industrial manufacturing, casting has evolved over the centuries to become a fundamental process in the creation of metal objects.

The age-old tradition of casting lives on in the intricate forms of jewelry and sculpture, where molten metal is transformed into works of art through careful molding and casting techniques. In the realm of modern industry, casting plays a vital role in the production of everything from engine parts to architectural details, showcasing the enduring legacy of this ancient craft.

Welding the Fabric of Metalworking

Welding, the process of joining metal through heat, has been a fundamental practice in metalworking since time immemorial. From the early days of forge welding to the modern techniques of construction and fabrication, welding has been a driving force behind the innovation and evolution of metalworking processes.

In the crucible of ancient forges, craftsmen mastered the art of welding through techniques such as forge welding and brazing, creating intricate metal joints that stood the test of time. Today, welding remains a cornerstone of modern industry, with applications ranging from skyscraper construction to delicate repair work, showcasing the versatility and enduring relevance of this ancient craft.

Sheet Metal Fabrication - Crafting the Thinnest Threads

Sheet metal fabrication, the art of shaping thin metal sheets into various products through cutting, bending and assembling, has a rich history that spans centuries of innovation and craftsmanship. From manual processes to advanced machinery, the evolution of sheet metal fabrication reflects the ever-changing landscape of metalworking.

In the fabled workshops of yore, artisans meticulously shaped thin metal sheets into intricate forms, a tradition that lives on in the industries of construction, automotive manufacturing and aerospace. The symphony of shears and presses resonates with the echoes of history, as modern technologies continue to push the boundaries of what is possible with sheet metal fabrication .

Repoussé and Chasing

Repoussé and chasing, techniques for shaping and detailing metal surfaces, have been cherished by artisans throughout history for their ability to imbue metal objects with intricate designs and textures. From ancient decorative arts to contemporary jewelry making, repoussé and chasing have remained a testament to the artistry and craftsmanship of metalworking.

In the golden age of ancient artistry, skilled craftsmen used repoussé and chasing techniques to create elaborate objects that captured the imagination and awe of onlookers. Today, these timeless techniques continue to shape the world of modern metalworking, bringing a touch of artistry and elegance to everything from fine jewelry to ornamental pieces.

Enameling - The Vibrant Palette of Metal

Enameling, the process of fusing powdered glass onto metal surfaces to add color and texture, has a storied history that dates back to ancient civilizations where jewelry and decorative objects were adorned with vibrant enamel finishes. From ancient techniques to modern applications, enameling has continued to captivate and inspire artists and craftspeople alike.

The ancient art of enameling lives on in contemporary jewelry making and decorative arts, where vibrant enamel colors bring a touch of vibrancy and sophistication to metal objects. In the realm of modern industry, enameling plays a vital role in creating durable and aesthetically pleasing finishes for a wide range of metal products, showcasing the enduring appeal and versatility of this ancient craft.

Advancing Ancient Techniques with Modern Technology

The marriage of ancient metalworking techniques with modern technology has ushered in a new era of innovation and creativity, pushing the boundaries of what is possible in the realm of metallurgy. From CAD/CAM design to 3D printing , advanced materials to high-tech alloys, the fusion of tradition and technology has opened up exciting new possibilities for artisans and engineers alike.

Final Words

The legacy of ancient metalworking techniques lives on in the intricate forms and elegant designs of contemporary metal objects, reminding us of the enduring relevance and innovation within this fascinating field. Let’s not forget to appreciate the craftsmanship and artistry behind these ancient techniques, for they are the threads that connect us to our past and guide us towards a brighter future in the world of metalworking.

Author: Richard Jegla(Sales Engineer)

Richard has been on The Federal Group team for 24 years and his knowledge spans a variety of mechanical engineering topics. When he isn't assisting his clients, he is routinely working on his motorcycles and off-road vehicle projects.

Hi seekers! Welcome to another article discussing a sensor from the MQ gas sensor series. Today, we are discussing the MQ-9 gas sensor, which can detect gases like carbon monoxide, CH4, and LPG. It has a long life and a simple structure, and the heart of this gas sensor is the sensing element on the heating circuit. Usually, such sensors are part of large projects where they sense the target gas and send a signal for any alarming condition.

We’ll begin the discussion with the basic introduction of this sensor in which we’ll discuss the basic parts and their duties. After that, we’ll move towards the datasheet elements and study this sensor's features, specifications, and other details. You will also see its working principles and diagrams to understand the concept. In the end, there will be a glance at the applications in which the MQ-8 gas sensor plays a vital role. Let’s hover over today’s first topic:

MQ-9 Gas Sensor Introduction

The MQ-9 gas sensor belongs to the MQ series, which has multiple sensors specialised for a particular gas. In the case of the MQ-9 gas sensor, the target gases are methane, propane, and other combustible gases that may be life-threatening if leaked. As the ambient concentration of target gases rises, the sensor diligently absorbs them at a higher rate, conveying their presence through analogue values at its analogue pin.

Let's focus on the fundamental components of this sophisticated sensor, unravelling its intricacies for a comprehensive understanding:

MQ-9 Gas Sensor Sensing Substrate

A ceramic material is present on the core of the MQ-9 base. It is usually alumina (Al2O3) that is responsible for providing the mechanical strength to the sensing element. The reason to use alumina is its high thermal stability and electrical resistance so that it does not provide any interference in the sensor’s values.

MQ-9 Gas Sensor Sensing Element

The heart of this sensor is the sensing element that absorbs the target gas and senses its presence. It is a small, cylindrical-shaped structure made with tin oxide (SnO2). It is wrapped around the ceramic material in the form of a uniform layer. 

MQ-9 Gas Sensor Heater Circuit

As mentioned before, the small heating circuit is present under the sensing element. It is a coil made of nichrome wire embedded within the substrate of ceramic material. This can heat the sensing element to around 300°C. This heat starts the work of the whole sensor. 

MQ-9 Gas Sensor Electrodes

The ceramic substrate has metallic contacts on both sides that are responsible for the interface between the sensing element and the circuit. These electrodes also allow electrical current to pass through the sensing element to create a change in the electrical conductance, and this is the basic way to sense the presence of gas. 

MQ-9 Gas Sensor Datasheet

Prior to the utilization of any electrical component, it is important to peruse the datasheet that outlines the product's intricate details. Presented below are fundamental considerations essential for an informed deployment of the MQ-9 gas sensor.

MQ-9 Gas Sensor Features

• One of the unique features of the MQ-9 that makes it different from other MQ series elements is its wide range of gas detection. It is not specialised for a single gas but can detect multiple gases, which makes it a versatile sensor. The list of detectable gases for this sensor is given below:

• Methane (CH4)

• Propane (C3H8)

• Liquefied petroleum gas (LPG)

• Carbon monoxide (CO)

• It is a more versatile and cost-effective gas sensor and, therefore, is preferred in fields like industries and home safety. 

• It has a simple structure that consumes fewer resources.

• It has a fast response time that allows prompt warnings and measures. 

• It has a compact and portable design that makes it suitable for different circuits. 

MQ-9 Gas Sensor Specifications

The following table shows the basic specifications of this sensor:

MQ-9 Gas Sensor Sensitivity Character

As mentioned before, the MQ-9 can detect multiple gases, but it is important to understand that the response time and sensitivity of this sensor are different for all of these. These factors depend on the chemical reaction between the sensing element and the target gas, and here is a comparison of the performance of the MQ-9 gas sensor with different gases in the form of a graph:

MQ-9 Gas Sensor Basic Circuit

The MQ-9 gas sensor has a simple and easy-to-understand circuit. Here is the diagram that shows the test loop of this device with the help of basic labels:

Here, 

VH = Heater voltage

Vc = Test voltage

VRL = Voltage on load resistance

RL = Load resistance

If you want to know more about the datasheet or want to study it in detail, then you can visit the following link:

MQ-9 Gas Sensor Pinout Configuration

The MQ-9 gas sensor has four pins. The description and details of each of them are mentioned below:

MQ-9 Gas Sensor Alternatives

Here is a list of the alternative options that can be used in place of MQ-9. The performance of these sensors is not identical to that of the MQ-9 but experts may use them in some projects:

• Figaro TGS series

• Sensirion SGP series

• Amphenol SGX series

• GasSense IR series

• PerkinElmer NDIR-1 series

Where to Buy MQ-9 Gas Sensor 

The electrical components, such as MQ-9 have a sensitive structure; therefore, always choose the best product from the best platforms for quality results. The following are some popular choices for such elements:

• eBay

• AliExpress

• Amazon

MQ-9 Gas Sensor Working Principle

The working principle of this sensor is similar to that of other MQ series sensors. It works on the chemiresistor working principle, which means the change in the electrical resistance of the sensing element results in the output values of this sensor. Here are the steps that will explain the previous statement:

MQ-9 Gas Sensor Substrate Heating

As soon as the sensor is powered on, the heating circuit starts increasing the substrate (alumina) temperature. The internal coil of the substrate heats it, and this change is uniformly distributed to the cylindrical shapes sensing element. 

MQ-9 Gas Sensor Depletion Region

The heated substrate maintains a temperature of 300 °C, and it stimulates the tin oxide to absorb the oxygen from the surroundings. Soon, the hydrogen ions start accumulating on its surface, and as a result, a depletion region is formed around the sensing element that increases the electrical conductivity of tin oxide. 

MQ-9 Gas Sensor Gas Absorption

The depletion region remains on the surface of tin oxide in the air until there is no target gas mixed in it. If any of the target gases are leaked into the air, they start reacting with the depletion region around the sensing element. This reaction results in the absorption of the depletion region. As a result, the electrical conductivity of the tin oxide increases as the sensor indicates this change in resistance through the analogue pin. In other words, the values of the electrical resistance are always present on the analogue pin, but sudden changes in the resistance are alarming on the analogue pin. The higher the target gas concentration, the more sudden and large changes are seen on the analogue pin.

MQ-9 Gas Sensor Gas Digital Value

The digital values show the presence or absence of the target gas without indicating its concentration. The digital pin shows only two outputs as mentioned in the pin description.

The signals from the digital and analogue pins are sent to the output device that indicates the results. 

MQ-9 Gas Sensor Physical Dimensions

The MQ-9 gas sensor does not have multiple packages. The size and dimension may vary from model to model, but usually, it is a compact product that can be used in different types of circuits. Here is the table that shows the general package dimensions of this sensor:

MQ-9 Gas Sensor Applications

The MQ-9 gas sensor finds extensive application in various projects, catering to significant domains. Below are key sectors where its utilization proves pivotal:

• Home Safety

• Industrial monitoring

• Environmental monitoring

• Portable gas detectors

• DIY projects (Air quality monitoring systems, smart home gas leak alarms, educational experiments)

Today, we have seen detailed information about the MQ-9 gas sensor. It is a versatile sensor that provides the sensing of multiple gases at a time. We commenced our exploration with a comprehensive introduction to the MQ-9 gas sensor. Progressing further, we moved towards the datasheet, unravelling its distinctive features and specifications. An in-depth exploration of the sensor's operational principles ensued. Finally, we comprehended its physical dimensions and explored the diverse spectrum of applications it caters to. I hope it was an informative article for you, and if you want to know more, you can contact us. 

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.