The document discusses oxygen sensors, which measure the proportion of oxygen in exhaust gases. It describes how oxygen sensors were developed in the 1960s and have since been important for pollution control in automobiles. The document outlines different types of oxygen sensors, including those used in automobile exhaust systems to optimize air-fuel ratios and reduce emissions. It explains how oxygen sensors work and the factors that determine their performance.
An oxygen sensor measures the proportion of oxygen in exhaust gases to help maintain the optimal air-fuel ratio for emissions control. It works with a three-way catalytic converter to reduce engine emissions. There are several types of oxygen sensors, including zirconia, titanium, and wide-band air-fuel ratio sensors. They function by changing voltage or resistance based on whether the air-fuel mixture is rich, lean, or stoichiometric. Maintaining proper oxygen sensor functioning is important for emissions control and engine performance.
The document summarizes an automotive fuel system report created by engineering students at Somali National University. It provides background on fuel systems and their importance, a brief history of their development, classifications of fuels, descriptions of key fuel system components like the fuel tank, lines, filters, pumps, and carburetor or injectors, as well as an overview of fuel additives and common types used.
Seminar report on modifications for ethanol enginesSughosh Deshmukh
This technical report summarizes modifications needed in a gasoline engine to enable it to run on ethanol fuel. It discusses changing the main jet, idle orifice, power valve, accelerator pump, compression ratio, cold weather starting, and thermostat. The report was submitted by Sughosh D. Deshmukh to his professor M. P. Joshi at Shri Ramdeobaba College of Engineering and Management in Nagpur, India to fulfill requirements for a mechanical engineering course.
The heart of an automobile is its engine, and the heart requires a constant and ingenuous supply of blood, fuel in this case. There had been carburetors faithfully doing this holy work, but technology never seizes to move up. Therefore, the latest offering is the fuel injector for petrol engin es. Though it all started with a simple objective of supplying a controlled amount of fuel at proper intervals of time, it’s, as of now, not as simple as that. With emission norms getting stricter and changing trends in engine technology – high-speed engines, Variable displacement engines, Hybrid engines, etc – it became more and more of a necessity than a luxury to improve the fuel supply system.
Today’s fuel injection unit not only improves engine performance, but also helps in giving a cleaner exhaust that too with a increased fuel economy. The objectives can be attained using a microprocessor that directs the injector using a number of various input parameters. These parameters include manifold temperatures, throttle position, ignition timing, engine speed, load, and a lot more of other factors. The various strategically placed sensors measures these physical quantities and convey the same to the processor in electronic signals. The paper deals with the brief functionality and basic concept of operation of a modern fuel injector used in petrol engines.
The document discusses fuel injectors, which inject fuel into cylinders in an atomized form and proper quantity. It first introduces fuel injectors and their history. It then discusses that fuel injectors can be mechanical or electronic, with mechanical using a single plunger piston and electronic working through an ECU signal. The document also covers the different types of injections and advantages of fuel injectors like improved fuel consumption, reduced emissions, and better performance.
The document describes a new type of engine called the "green engine" that aims to address global issues related to energy and pollution. It has several innovative technical features that allow it to operate with higher efficiency and near-zero emissions compared to conventional piston engines. The green engine works in six phases - intake, compression, mixing, combustion, power, and exhaust - using a design with vanes and rotors rather than pistons. Its key advantages include small size, limited parts, multi-fuel capability, high efficiency, and minimal emissions, making it a promising new technology for automotive and other applications.
The document discusses fuel injection systems. It begins with an introduction to fuel injection, noting that it mixes fuel with air and has replaced carburetors. It then describes the construction and working of fuel injection systems, including the fuel injector which injects fuel under high pressure. Different types of fuel injection systems are covered, including multi-point fuel injection and turbocharged direct injection. Advantages are discussed such as increased engine performance, decreased emissions, and increased efficiency. The document concludes that fuel injection and ignition technologies have revolutionized automobiles while allowing for better resource utilization and reduced pollution.
This document discusses using alcohol as an alternative fuel in spark ignition engines. It outlines that E85 fuel is a blend of 85% ethanol and 15% gasoline that can be used in flexible fuel vehicles. The document also discusses the properties of ethanol including its production from crops, blending with gasoline, use as an octane booster, and ability to reduce greenhouse gas emissions compared to gasoline. It notes both advantages, such as higher octane ratings, and disadvantages, like lower energy content, of using alcohols like ethanol as a vehicle fuel.
An oxygen sensor measures the proportion of oxygen in exhaust gases to help maintain the optimal air-fuel ratio for emissions control. It works with a three-way catalytic converter to reduce engine emissions. There are several types of oxygen sensors, including zirconia, titanium, and wide-band air-fuel ratio sensors. They function by changing voltage or resistance based on whether the air-fuel mixture is rich, lean, or stoichiometric. Maintaining proper oxygen sensor functioning is important for emissions control and engine performance.
The document summarizes an automotive fuel system report created by engineering students at Somali National University. It provides background on fuel systems and their importance, a brief history of their development, classifications of fuels, descriptions of key fuel system components like the fuel tank, lines, filters, pumps, and carburetor or injectors, as well as an overview of fuel additives and common types used.
Seminar report on modifications for ethanol enginesSughosh Deshmukh
This technical report summarizes modifications needed in a gasoline engine to enable it to run on ethanol fuel. It discusses changing the main jet, idle orifice, power valve, accelerator pump, compression ratio, cold weather starting, and thermostat. The report was submitted by Sughosh D. Deshmukh to his professor M. P. Joshi at Shri Ramdeobaba College of Engineering and Management in Nagpur, India to fulfill requirements for a mechanical engineering course.
The heart of an automobile is its engine, and the heart requires a constant and ingenuous supply of blood, fuel in this case. There had been carburetors faithfully doing this holy work, but technology never seizes to move up. Therefore, the latest offering is the fuel injector for petrol engin es. Though it all started with a simple objective of supplying a controlled amount of fuel at proper intervals of time, it’s, as of now, not as simple as that. With emission norms getting stricter and changing trends in engine technology – high-speed engines, Variable displacement engines, Hybrid engines, etc – it became more and more of a necessity than a luxury to improve the fuel supply system.
Today’s fuel injection unit not only improves engine performance, but also helps in giving a cleaner exhaust that too with a increased fuel economy. The objectives can be attained using a microprocessor that directs the injector using a number of various input parameters. These parameters include manifold temperatures, throttle position, ignition timing, engine speed, load, and a lot more of other factors. The various strategically placed sensors measures these physical quantities and convey the same to the processor in electronic signals. The paper deals with the brief functionality and basic concept of operation of a modern fuel injector used in petrol engines.
The document discusses fuel injectors, which inject fuel into cylinders in an atomized form and proper quantity. It first introduces fuel injectors and their history. It then discusses that fuel injectors can be mechanical or electronic, with mechanical using a single plunger piston and electronic working through an ECU signal. The document also covers the different types of injections and advantages of fuel injectors like improved fuel consumption, reduced emissions, and better performance.
The document describes a new type of engine called the "green engine" that aims to address global issues related to energy and pollution. It has several innovative technical features that allow it to operate with higher efficiency and near-zero emissions compared to conventional piston engines. The green engine works in six phases - intake, compression, mixing, combustion, power, and exhaust - using a design with vanes and rotors rather than pistons. Its key advantages include small size, limited parts, multi-fuel capability, high efficiency, and minimal emissions, making it a promising new technology for automotive and other applications.
The document discusses fuel injection systems. It begins with an introduction to fuel injection, noting that it mixes fuel with air and has replaced carburetors. It then describes the construction and working of fuel injection systems, including the fuel injector which injects fuel under high pressure. Different types of fuel injection systems are covered, including multi-point fuel injection and turbocharged direct injection. Advantages are discussed such as increased engine performance, decreased emissions, and increased efficiency. The document concludes that fuel injection and ignition technologies have revolutionized automobiles while allowing for better resource utilization and reduced pollution.
This document discusses using alcohol as an alternative fuel in spark ignition engines. It outlines that E85 fuel is a blend of 85% ethanol and 15% gasoline that can be used in flexible fuel vehicles. The document also discusses the properties of ethanol including its production from crops, blending with gasoline, use as an octane booster, and ability to reduce greenhouse gas emissions compared to gasoline. It notes both advantages, such as higher octane ratings, and disadvantages, like lower energy content, of using alcohols like ethanol as a vehicle fuel.
The document describes the basic process of how brakes work in a vehicle. It explains that pressing the brake pedal applies pressure through a brake booster and master cylinder to brake lines and fluid. This fluid pressure is converted to mechanical pressure by calipers to force brake pads against rotors, slowing the wheels and ultimately stopping the vehicle through traction provided by the tires. Key components include the pedal, booster, master cylinder, lines, calipers, pads, rotors, and tires.
The document discusses advancements in automobile safety technologies. It describes how anti-lock braking systems (ABS) work to prevent wheel lock and maintain steering control during braking. ABS uses sensors to monitor wheel speed and a microprocessor to compare speeds and control valves to rapidly brake and release wheels. This allows for shorter stopping distances. Newer systems also control front-to-rear brake bias electronically. Airbags are described as occupant restraint systems that inflate during impacts to cushion occupants. Different types like driver, passenger and curtain airbags are discussed. Traction control builds on ABS to control engine and braking for individual wheels to maintain traction on slippery surfaces. Automakers now spend billions annually developing new safety technologies.
The document provides an overview of electric vehicles including their history and types. It discusses how the earliest electric vehicles emerged in the late 1800s and became popular in the early 1900s. It describes different types of electric vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). It also discusses the key forces that affect electric vehicle power trains including rolling resistance, aerodynamic drag, and gradient forces due to road inclines.
The document discusses compressed air technology (CAT) as a potential zero-emission vehicle technology. It provides details on how CAT vehicles work, including storing compressed air in carbon fiber tanks at 300 bars, releasing it to power an engine in multiple expansion stages for efficient energy use. CAT vehicles are compared to electric vehicles, showing CAT's lower costs, faster refueling time of under 4 minutes, and lower operating costs than gasoline vehicles. The document concludes that CAT is a feasible solution for reducing environmental pollution from fossil fuel vehicles as it produces no emissions.
Battery electric vehicle, plug-in hybrid electric vehicle, conventional vehicle and now fuel cell vehicles. With the advancement of technology new inventions have been made in auto industry in past few years. Do you know what fuel cell vehicle is? This presentation attributes the features of fuel cell vehicles and how it differs from battery electric, plug-in hybrid electric and conventional vehicles. Also have some light on its feasibility and merits & demerits.
This document discusses drive by wire technology. It begins with an introduction and overview of the history and working principle. It then describes the different systems within drive by wire, including steer by wire, throttle by wire, and brake by wire. Each system replaces the traditional mechanical control systems with electronic sensors and actuators controlled by an engine control module. The advantages are more design flexibility, weight reduction, improved safety and performance, and potential for advanced driver assistance features. The document concludes by discussing future applications and trends toward more customizable control interfaces using drive by wire technology.
This document summarizes a seminar presentation on Idle Stop Start (I3S) technology. I3S technology automatically shuts off the engine when idling to reduce fuel consumption and emissions. The technology was first developed by Toyota in 1964 and has improved fuel economy by about 10% according to tests. I3S works by using a battery, electric generator, starter, and sensor to restart the engine within 350 milliseconds when needed. I3S reduces fuel consumption by 5-10% in city driving and lowers CO2 emissions by 7-8%. While the technology cuts costs and emissions, it provides only minor fuel savings compared to hybrid systems and some vehicle functions may not work with the engine off. I3S
The emission control system reduces pollutants from vehicle exhaust by using several components. The positive crankcase ventilation (PCV) system and evaporative emission (EVAP) system reduce hydrocarbons, while the exhaust gas recirculation (EGR) system and three-way catalytic converter (TWC) lower nitrogen oxides and carbon monoxide. These work together to minimize harmful emissions like carbon monoxide, hydrocarbons, nitrogen oxides, sulfur oxides, and particulate matter that can impact human health.
Emission control technologies for automobilesShiril Saju
- The document discusses various emission control technologies used in automobiles to reduce air pollutants from vehicle exhaust. It outlines technologies like electronic fuel injection systems, multi-point fuel injection, direct injection systems, and catalytic converters.
- Key pollutants of concern from vehicles include hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides. Emission standards called Bharat Stage standards are instituted in India based on European EURO standards to regulate these pollutants.
- The technologies discussed aim to more efficiently and completely combust fuel to reduce emissions through things like precise fuel metering and computerized engine management. Catalytic converters also help to break down remaining pollutants in
internal combustion engines are discussed including combustion behaviourmp poonia
The document provides information on engine performance and terminology. It discusses how engines convert the heat of burning fuel into useful energy. It explains that engine efficiency is typically much less than 100% due to factors like friction and heat loss. It also discusses different types of engines like Otto and Diesel engines, and key engine components and metrics like bore, stroke, displacement, compression ratio, power, and torque. It provides details on fuel types, properties, and requirements for different engines. Overall, the document is a technical overview of engine performance and key concepts.
An electric fuel pump is a device used to power an automobile's engine by directing the fuel through electronic means. It is an alternative to manual fuel pump system and is considered to be a better use of technology with the function and operation of vehicles. An electric fuel pump is mounted inside the fuel tank and operated by the electrical systems of the vehicle. Electric fuel pump can deliver fuel at high pressure in order to meet the requirements of the engine.
This document discusses motorcycle suspension systems. It describes that motorcycles use suspension to provide safety, comfort and handling by isolating riders from road bumps and vibrations. The most common front suspension is the telescopic fork, which acts like a hydraulic shock absorber. Rear suspension usually involves a swingarm and either twin shock absorbers or a mono shock absorber. While twin shocks provide more wheel travel, mono shocks now offer better performance, handling, stability and are easier to adjust. The document concludes that the project will use a telescopic fork for front suspension and a mono shock absorber for rear suspension.
Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent
Multi Point Fuel Injection System (MPFI) supplies the proper ratio of gasoline and air to engine cylinders without using a carburetor. It varies piston speed using advanced sensors controlled by the Engine Control Unit (ECU). MPFI systems are classified as either port injection or throttle injection based on the placement of the injectors. Port injection sprays fuel into the intake manifold near the intake ports, while throttle injection is similar to a carburetor with injectors controlling fuel mixing. The ECU primarily controls ignition timing and fuel injection quality based on sensor data. MPFI provides benefits like lower costs, higher efficiency, reduced maintenance, and higher engine power compared to carbureted systems.
The document discusses Digital Twin Spark Ignition (DTS-I) technology used in some 4-stroke petrol engines. DTS-I uses two spark plugs placed at opposite ends of the combustion chamber to more completely burn the air-fuel mixture. This leads to increased power, reduced emissions, and better starting compared to a conventional single spark plug engine. Some motorcycles that use DTS-I technology include models from Bajaj like the Pulsar 135, 150, 180, and 200.
This document discusses catalytic converters and their role in reducing vehicle emissions. It notes that catalytic converters use precious metals to convert harmful exhaust gases like carbon monoxide, unburned hydrocarbons, and nitrogen oxides into less harmful emissions. Stricter emission standards over time have led to advances in catalytic converter design and materials. The document provides details on the components and chemical reactions that occur in both two-way and three-way catalytic converters.
The document discusses electronic stability control systems in vehicles. Electronic stability control regulates engine power and braking to individual wheels to control stability. It summarizes that modern vehicles use multiple controllers rather than a single controller, with a power train control module coordinating various controllers for sections like chassis, body electronics, driver information, powertrain, and safety systems. Networking allows the controllers to share sensor information and work as a unit.
The green engine is an innovative new engine design that is more efficient and produces nearly zero emissions compared to conventional engines. It works using six phases: intake, compression, mixing, combustion, power, and exhaust. Key features include vanes, rotors, and fuel injectors that compress and ignite air and fuel mixtures to generate power. The green engine offers advantages like smaller size, ability to run on multiple fuels, near-zero emissions, and higher efficiency. Potential applications include use in cars, planes, generators and more to provide cleaner and more sustainable power.
Exhaust Gas Recirculation is an effective method for NOx control. The exhaust gases mainly consist of carbon dioxide, nitrogen, etc. and the mixture has higher specific heat compared to atmospheric air. Re-circulated exhaust gas displaces fresh air entering the combustion chamber with carbon dioxide and water vapor present in engine exhaust. As a consequence of this air displacement, lower amount of oxygen in the intake mixture is available for combustion. Reduced oxygen available for combustion lowers the effective air–fuel ratio. This effective reduction in air–fuel ratio affects exhaust emissions
This document describes research on an oxygen sensor using an n-type semiconductor. Key points:
- The sensor measures trace amounts of oxygen by desorbing and adsorbing oxygen onto an n-type semiconductor surface using UV light and measuring electrical resistance.
- Using an ultrathin film comparable to the polaron diameter allows the sensor to be more sensitive to low and high oxygen concentrations by changing the polaron diameter and conductivity.
- The sensor showed good performance in measuring oxygen concentrations from 10-15 to 10-5 with resistance changing over several orders of magnitude.
How an oxygen sensor works in an automobile??Aayushi Nanda
The oxygen sensor plays a critical role in providing optimum engine performance with minimal emissions...The ppt describes all about the oxygen sensor operation in our automobile and how ECU can manipulate the air-fuel ratio in order to minimize the emissions.
The document describes the basic process of how brakes work in a vehicle. It explains that pressing the brake pedal applies pressure through a brake booster and master cylinder to brake lines and fluid. This fluid pressure is converted to mechanical pressure by calipers to force brake pads against rotors, slowing the wheels and ultimately stopping the vehicle through traction provided by the tires. Key components include the pedal, booster, master cylinder, lines, calipers, pads, rotors, and tires.
The document discusses advancements in automobile safety technologies. It describes how anti-lock braking systems (ABS) work to prevent wheel lock and maintain steering control during braking. ABS uses sensors to monitor wheel speed and a microprocessor to compare speeds and control valves to rapidly brake and release wheels. This allows for shorter stopping distances. Newer systems also control front-to-rear brake bias electronically. Airbags are described as occupant restraint systems that inflate during impacts to cushion occupants. Different types like driver, passenger and curtain airbags are discussed. Traction control builds on ABS to control engine and braking for individual wheels to maintain traction on slippery surfaces. Automakers now spend billions annually developing new safety technologies.
The document provides an overview of electric vehicles including their history and types. It discusses how the earliest electric vehicles emerged in the late 1800s and became popular in the early 1900s. It describes different types of electric vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). It also discusses the key forces that affect electric vehicle power trains including rolling resistance, aerodynamic drag, and gradient forces due to road inclines.
The document discusses compressed air technology (CAT) as a potential zero-emission vehicle technology. It provides details on how CAT vehicles work, including storing compressed air in carbon fiber tanks at 300 bars, releasing it to power an engine in multiple expansion stages for efficient energy use. CAT vehicles are compared to electric vehicles, showing CAT's lower costs, faster refueling time of under 4 minutes, and lower operating costs than gasoline vehicles. The document concludes that CAT is a feasible solution for reducing environmental pollution from fossil fuel vehicles as it produces no emissions.
Battery electric vehicle, plug-in hybrid electric vehicle, conventional vehicle and now fuel cell vehicles. With the advancement of technology new inventions have been made in auto industry in past few years. Do you know what fuel cell vehicle is? This presentation attributes the features of fuel cell vehicles and how it differs from battery electric, plug-in hybrid electric and conventional vehicles. Also have some light on its feasibility and merits & demerits.
This document discusses drive by wire technology. It begins with an introduction and overview of the history and working principle. It then describes the different systems within drive by wire, including steer by wire, throttle by wire, and brake by wire. Each system replaces the traditional mechanical control systems with electronic sensors and actuators controlled by an engine control module. The advantages are more design flexibility, weight reduction, improved safety and performance, and potential for advanced driver assistance features. The document concludes by discussing future applications and trends toward more customizable control interfaces using drive by wire technology.
This document summarizes a seminar presentation on Idle Stop Start (I3S) technology. I3S technology automatically shuts off the engine when idling to reduce fuel consumption and emissions. The technology was first developed by Toyota in 1964 and has improved fuel economy by about 10% according to tests. I3S works by using a battery, electric generator, starter, and sensor to restart the engine within 350 milliseconds when needed. I3S reduces fuel consumption by 5-10% in city driving and lowers CO2 emissions by 7-8%. While the technology cuts costs and emissions, it provides only minor fuel savings compared to hybrid systems and some vehicle functions may not work with the engine off. I3S
The emission control system reduces pollutants from vehicle exhaust by using several components. The positive crankcase ventilation (PCV) system and evaporative emission (EVAP) system reduce hydrocarbons, while the exhaust gas recirculation (EGR) system and three-way catalytic converter (TWC) lower nitrogen oxides and carbon monoxide. These work together to minimize harmful emissions like carbon monoxide, hydrocarbons, nitrogen oxides, sulfur oxides, and particulate matter that can impact human health.
Emission control technologies for automobilesShiril Saju
- The document discusses various emission control technologies used in automobiles to reduce air pollutants from vehicle exhaust. It outlines technologies like electronic fuel injection systems, multi-point fuel injection, direct injection systems, and catalytic converters.
- Key pollutants of concern from vehicles include hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides. Emission standards called Bharat Stage standards are instituted in India based on European EURO standards to regulate these pollutants.
- The technologies discussed aim to more efficiently and completely combust fuel to reduce emissions through things like precise fuel metering and computerized engine management. Catalytic converters also help to break down remaining pollutants in
internal combustion engines are discussed including combustion behaviourmp poonia
The document provides information on engine performance and terminology. It discusses how engines convert the heat of burning fuel into useful energy. It explains that engine efficiency is typically much less than 100% due to factors like friction and heat loss. It also discusses different types of engines like Otto and Diesel engines, and key engine components and metrics like bore, stroke, displacement, compression ratio, power, and torque. It provides details on fuel types, properties, and requirements for different engines. Overall, the document is a technical overview of engine performance and key concepts.
An electric fuel pump is a device used to power an automobile's engine by directing the fuel through electronic means. It is an alternative to manual fuel pump system and is considered to be a better use of technology with the function and operation of vehicles. An electric fuel pump is mounted inside the fuel tank and operated by the electrical systems of the vehicle. Electric fuel pump can deliver fuel at high pressure in order to meet the requirements of the engine.
This document discusses motorcycle suspension systems. It describes that motorcycles use suspension to provide safety, comfort and handling by isolating riders from road bumps and vibrations. The most common front suspension is the telescopic fork, which acts like a hydraulic shock absorber. Rear suspension usually involves a swingarm and either twin shock absorbers or a mono shock absorber. While twin shocks provide more wheel travel, mono shocks now offer better performance, handling, stability and are easier to adjust. The document concludes that the project will use a telescopic fork for front suspension and a mono shock absorber for rear suspension.
Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent
Multi Point Fuel Injection System (MPFI) supplies the proper ratio of gasoline and air to engine cylinders without using a carburetor. It varies piston speed using advanced sensors controlled by the Engine Control Unit (ECU). MPFI systems are classified as either port injection or throttle injection based on the placement of the injectors. Port injection sprays fuel into the intake manifold near the intake ports, while throttle injection is similar to a carburetor with injectors controlling fuel mixing. The ECU primarily controls ignition timing and fuel injection quality based on sensor data. MPFI provides benefits like lower costs, higher efficiency, reduced maintenance, and higher engine power compared to carbureted systems.
The document discusses Digital Twin Spark Ignition (DTS-I) technology used in some 4-stroke petrol engines. DTS-I uses two spark plugs placed at opposite ends of the combustion chamber to more completely burn the air-fuel mixture. This leads to increased power, reduced emissions, and better starting compared to a conventional single spark plug engine. Some motorcycles that use DTS-I technology include models from Bajaj like the Pulsar 135, 150, 180, and 200.
This document discusses catalytic converters and their role in reducing vehicle emissions. It notes that catalytic converters use precious metals to convert harmful exhaust gases like carbon monoxide, unburned hydrocarbons, and nitrogen oxides into less harmful emissions. Stricter emission standards over time have led to advances in catalytic converter design and materials. The document provides details on the components and chemical reactions that occur in both two-way and three-way catalytic converters.
The document discusses electronic stability control systems in vehicles. Electronic stability control regulates engine power and braking to individual wheels to control stability. It summarizes that modern vehicles use multiple controllers rather than a single controller, with a power train control module coordinating various controllers for sections like chassis, body electronics, driver information, powertrain, and safety systems. Networking allows the controllers to share sensor information and work as a unit.
The green engine is an innovative new engine design that is more efficient and produces nearly zero emissions compared to conventional engines. It works using six phases: intake, compression, mixing, combustion, power, and exhaust. Key features include vanes, rotors, and fuel injectors that compress and ignite air and fuel mixtures to generate power. The green engine offers advantages like smaller size, ability to run on multiple fuels, near-zero emissions, and higher efficiency. Potential applications include use in cars, planes, generators and more to provide cleaner and more sustainable power.
Exhaust Gas Recirculation is an effective method for NOx control. The exhaust gases mainly consist of carbon dioxide, nitrogen, etc. and the mixture has higher specific heat compared to atmospheric air. Re-circulated exhaust gas displaces fresh air entering the combustion chamber with carbon dioxide and water vapor present in engine exhaust. As a consequence of this air displacement, lower amount of oxygen in the intake mixture is available for combustion. Reduced oxygen available for combustion lowers the effective air–fuel ratio. This effective reduction in air–fuel ratio affects exhaust emissions
This document describes research on an oxygen sensor using an n-type semiconductor. Key points:
- The sensor measures trace amounts of oxygen by desorbing and adsorbing oxygen onto an n-type semiconductor surface using UV light and measuring electrical resistance.
- Using an ultrathin film comparable to the polaron diameter allows the sensor to be more sensitive to low and high oxygen concentrations by changing the polaron diameter and conductivity.
- The sensor showed good performance in measuring oxygen concentrations from 10-15 to 10-5 with resistance changing over several orders of magnitude.
How an oxygen sensor works in an automobile??Aayushi Nanda
The oxygen sensor plays a critical role in providing optimum engine performance with minimal emissions...The ppt describes all about the oxygen sensor operation in our automobile and how ECU can manipulate the air-fuel ratio in order to minimize the emissions.
This document describes an oxygen sensing technology developed by Dr. Nuno Faria and Prof. Jonathan Powell at the Medical Research Council in Cambridge, UK. The technology uses a cheap modification of mineral structures to create an oxygen sensor that provides an irreversible color change. Key features include a clearly visible color change, tunable color and oxygen sensitivity, low cost and safe materials, and potential incorporation into materials like packaging. The sensors are composed of metal oxide particles modified with organic ligands to control the color change triggered by oxygen exposure.
The document summarizes the evaluation of a low-cost oxygen analyzer designed for use in hospitals in developing countries. Key points:
1) The analyzer uses a zinc-air battery that produces a voltage output linearly related to oxygen concentration to indicate concentration via colored LED lights, providing a simple, affordable way to ensure respiratory devices deliver optimal oxygen levels.
2) Prototypes accurately detected oxygen concentrations in testing, with an estimated manufacturing cost of $5 and proposed sale price of $15, much lower than existing analyzers costing $220.
3) Feedback from healthcare providers suggested modifications like a digital readout or alarm and integrating the device directly into oxygen machines to enhance usability and adoption.
This document provides an overview of the course IP0504 MACHINE TOOL DESIGN. The objectives of the course are to help students understand the concepts, develop a conceptual framework, and apply the knowledge to real-life problems. The course covers topics such as the design of machine tool drives, structures, guideways, power screws, spindles, and spindle supports. Evaluation is based on exams and outcomes include applying the content to industrial problems, undertaking design projects, and identifying areas for further research.
This document discusses computer-aided process planning (CAPP). It defines process planning as the systematic determination of manufacturing methods to produce a part from raw materials to finished form. CAPP uses computers to assist process planners by storing and retrieving data, or automatically generating process plans for simple shapes. There are two main CAPP approaches: the variant approach retrieves existing generic plans and edits them, while the generative approach creates new plans from scratch without human intervention. Both have advantages like reduced planning time and costs, but the generative approach can plan new parts more easily and provide detailed automation control information.
this is a presentation i made to give some introduction to the backward learning algorithm hope it would be use full.Many places were referred to get information here
Why choose GDI over other truss design outsourcing firms? One word will summarize: integrity!This slide will tell you why in detail.
Gould Design Inc. is a family owned and operated establishment partnered with MiTek USA and MiTek Canada. Specializing in remote truss design, our staff’s knowledge & experience extend throughout the US, into Canada, even Europe and beyond. GDI carries liability insurance and software licensing rights. In total, our team of specialists have over 250 years of component design experience and offer an extensive variety of real-time field knowledge relating to engineered design and application.
Vision Statement:
Extensive research, combined with breakthrough technologies focusing on industry innovation provides the springboard for GDI's professional development program. Utilizing communication and "real-world" experience in construction applications allows the flexibility required to successfully satisfy a unique variety of customer needs.
Mission Statement:
Providing design solutions to component manufacturers with unique requirements, while maintaining quality and timely performance, optimally suited to your individual needs.
Value Statement:
Garnishing relationships with customers and employees through integrity and professionalism, communication and ethics, resulting with increased efficiency and savings for the customer's bottom line.
This document discusses group technology and computer aided process planning. It defines group technology as identifying and grouping similar parts to take advantage of their common design and production characteristics. The key benefits of group technology are outlined. Implementation involves identifying part families and rearranging production machines into cells dedicated to each family. Various part classification and coding systems used in group technology are also described.
An engine speed sensor measures the rate at which the crankshaft spins by detecting interruptions in the magnetic field caused by notches on the crankshaft. It sends this speed information to the engine control module (ECM) which uses it to control ignition timing and other engine functions. There are two main types - magnetic sensors which generate an alternating current signal from a magnet, and Hall effect sensors which use blades to disrupt a magnetic field and produce an on/off signal read by the ECM.
The document discusses two main types of oxygen analyzers: zirconia and paramagnetic. Zirconia analyzers work by generating a voltage based on the difference in oxygen concentration between a process gas and reference gas in contact with a zirconia element. Paramagnetic analyzers detect oxygen concentration based on the displacement of a dumbbell in a magnetic field caused by oxygen's paramagnetic properties. The document also provides details on calibrating, testing, and maintaining zirconia oxygen analyzers.
The document discusses zirconia oxygen analyzers and their calibration. It provides details on:
- Zirconia oxygen analyzers measure oxygen concentration using air as a reference gas, but the oxygen concentration of air can vary with temperature and humidity, causing measurement errors.
- There are two main types of zirconia oxygen analysis - concentration cell systems and limiting current types - which generate electromotive forces or currents related to oxygen concentration.
- Calibration of the analyzers is important and can be done with either one-point or two-point methods using span and/or zero gases to establish calibration curves and correct for drift. Frequent calibration helps account for sensor degradation over time.
A fuel gauge is a device that measures the fuel level present in the vehicle. It consists of a sensing or a sending unit which helps to measure the amount of fuel. A gauge or indicator which is placed outside the fuel tank uses the information from the sensing unit to give the measure of fuel.
Detection Methods:
There are five types of detection methods which are as:
Catalytic oxidation detectors
Electrochemical detectors
Optical detectors
Electrical conductivity (semiconductors) detectors
Chemical adsorbents detectors.
Deep explanation of gas sensors for engineering studentsDayalAnand
The document discusses gas sensors. It begins by defining a sensor and listing common sensor applications. It then defines gas sensors as a subclass of chemical sensors that measure the concentration of gas. Various gas sensing technologies are described, including metal oxide, capacitive, acoustic, calorimetric, optical, and electrochemical sensors. Metal oxide sensors detect gas concentration changes by measuring resistance changes of a thin film. Capacitive sensors measure dielectric constant changes. Acoustic sensors use piezoelectric materials. Calorimetric sensors detect heat changes from gas combustion. Optical sensors use techniques like ellipsometry and spectroscopy. Electrochemical sensors create current from gas oxidation and reduction reactions. Applications and advantages of gas sensors
Electrochemical carbon monoxide sensors require regular maintenance to function properly and maximize their lifespan. They work by measuring the current produced from oxidation and reduction chemical reactions between electrodes and electrolytes when exposed to carbon monoxide gas. Typically, electrochemical gas sensors can operate for one to three years, but following manufacturer recommended calibration procedures every six months can extend their lifespan to five to seven years. It is important to calibrate the sensors regularly given the toxicity of carbon monoxide and potential safety consequences if the sensors provide inaccurate readings over time.
This document discusses gas sensors, including their applications, examples, and operating principles. It describes several types of gas sensors such as metal oxide, capacitive, acoustic, calorimetric, optical, and electrochemical sensors. Specific gas sensors for carbon monoxide, carbon dioxide, and hydrogen are examined in more detail. The document provides an overview of the technology and functioning of various gas sensing devices.
An emission gas analyzer measures the concentration of gases in exhaust, like carbon monoxide, to assess combustion efficiency and emissions. It discusses different types of gas analyzers like Pellistor/Catalytic Bead, Point/Non-Dispersive Infrared, Tunable/Enhanced Laser Diode Spectroscopy, and Electrochemical analyzers. The document also explains measuring the Lambda coefficient to evaluate lean or rich mixtures, and how the Enerac Model 700 portable emissions monitor can accurately measure gases like NOx with sensors, storage, and software.
Oxygen Excess Control of Industrial Combustion Through The Use of Automotive ...drboon
The objective of this study is to present a simple and low cost method of determining the flue gases oxygen concentration. The method makes use of the Lambda sensor, a part of the fuel injection system of the modern automobile’s engine. A combustion chamber was mounted with a heated Lambda sensor installed in its chimney. Residual oxygen concentrations in the flue gases were estimated by the use of the Nernst equation and compared to a reference combustion analyser. The observed average deviation in the measurements was of about 5 % which is in the range of interest to the industrial combustion.
Monitoring Industrial Combustion Through Automotive Oxygen Sensordrboon
The monitoring of oxygen percentage in flue gases is one of various ways of controlling efficiency and emissions of industrial combustion. In general, flue gases analyzers are expensive and not accessible to small scale industries. The automotive Lambda sensor is an oxygen sensor which controls the electronic injection of the modern internal combustion vehicles. The aim of this study is to present two methods of measuring the oxygen concentration in flue gases of industrial combustion by the use of the automotive Lambda sensor. One method uses the voltage signals of a heated Lambda sensor and the other one uses the Current Reversal Mode (CRM) of operation of such sensor. Results presented in this article show that such methods are effective to control industrial combustion.
This document presents an intelligent monitoring system to protect mine workers from carbon monoxide poisoning and cyanidation. The system uses sensors in a wearable helmet including a pulse oximeter to monitor workers' hemoglobin levels, a gas sensor to detect carbon monoxide, and a pH sensor to check acidity during gold mining. If carbon monoxide is detected, an exhaust fan will turn on automatically. If acidity increases beyond a safe level, the system will pump sodium hydroxide to neutralize it. All sensor readings will display on an LCD and sound an alarm at a central location. The system aims to enhance mine worker safety by monitoring multiple health parameters compared to previous single-parameter systems.
Gas chromatography–mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample.[1] Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation, food and flavor analysis, and identification of unknown samples, including that of material samples obtained from planet Mars during probe missions as early as the 1970s. GC-MS can also be used in airport security to detect substances in luggage or on human beings. Additionally, it can identify trace elements in materials that were previously thought to have disintegrated beyond identification. Like liquid chromatography–mass spectrometry, it allows analysis and detection even of tiny amounts of a substance.[2]
GC-MS has been regarded as a "gold standard" for forensic substance identification because it is used to perform a 100% specific test, which positively identifies the presence of a particular substance. A nonspecific test merely indicates that any of several in a category of substances is present. Although a nonspecific test could statistically suggest the identity of the substance, this could lead to false positive identification. However, the high temperatures (300°C) used in the GC-MS injection port (and oven) can result in thermal degradation of injected molecules,[3] thus resulting in the measurement of degradation products instead of the actual molecule(s) of interest.The first on-line coupling of gas chromatography to a mass spectrometer was reported in the late 1950s.[4][5] An interest in coupling the methods had been suggested as early as December 1954.
Design and Development of Catalytic Converter for Reduction of Pollution by U...YogeshIJTSRD
The use of fossil fuels in automobiles mainly HC, CO and NOX which produce harmful green house gases. The main objective of catalytic converter is to reduce and control effect of harmful pollutants by converting toxic CO and NOX to non toxic CO2and H2O. CFD analysis is done in the present study of catalytic converter by taking three different materials for the make of catalytic converter such as stainless steel, Grey cast iron and aluminum at the time by varying different fluids such as methane, ethane and nitrogen at varying speeds of 2000 and2500R.P.M. V. Saran Tej | M. Rakesh Kumar | N. Satya Sandeep | N. Sai "Design and Development of Catalytic Converter for Reduction of Pollution by Using Transient and CFD Analysis" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43784.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/43784/design-and-development-of-catalytic-converter-for-reduction-of-pollution-by-using-transient-and-cfd-analysis/v-saran-tej
IRJET- Inquisitive Analytics of Diverse Exhaust System Contingent to PollutionIRJET Journal
This document discusses the role of vehicle exhaust systems in reducing air pollution. It analyzes data from vehicles with short, medium, and long exhaust systems. The results show that vehicles with longer exhaust systems produce higher emissions of carbon monoxide and hydrocarbons compared to vehicles with shorter exhaust systems. This is because longer exhaust systems increase back pressure, reducing engine efficiency and increasing fuel consumption and emissions. To reduce pollution, exhaust systems should have minimum length to limit back pressure.
SIMULATION OF MEMS MICROHOTPLATE FOR METAL OXIDE GAS SENSORS: REVIEWIJEEE
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The document describes a system called ESPM that is designed to reduce CO2 emissions from vehicles in India. It works by installing an electrostatic precipitator in the exhaust system. The precipitator uses high voltage electrodes to charge particulate matter in the exhaust gas and plates to collect the charged particles, reducing emissions. Testing showed the system reduced CO2 levels in a vehicle's exhaust from 78.39% to 53.22%. The system aims to help control increasing vehicle pollution in India in an efficient and cost-effective way.
Practical Issues of Combustion Oxygen Measurement Specifically Related to NOx...Arjay Automation
Power plants concerned with lowering NOx emissions are making tremendous changes to accommodate EPA regulatory requirements. A substantial number of these changes include the expansion and upgrade of the plant combustion oxygen measurement equipment. There is a striking relationship between the number of NOx reductions projects and the sales quantity of insitu oxygen detectors. The reason is that power plant betterment groups, operators, boiler manufacturers and engineering firms understand the direct relationship between NOx and excess air in the combustion process.
An area of daily practical importance to boiler operators and I&C teams are the common problems with insitu oxygen measurements. This paper focuses on the practical issues of combustion oxygen measurement as they relate to specifically to fuel usage and NOx emissions.
Read the entire white paper, courtesy of Yokogawa Corporation of America here.
IRJET- Design of Eco Friendly System in Automobile for Environmental SafetyIRJET Journal
This document discusses the design of an eco-friendly system to monitor vehicle emissions. The system would use sensors to measure levels of harmful gases in a vehicle's exhaust, like carbon monoxide, nitrogen oxides, hydrocarbons and oxygen. It would display the emission levels to the driver using an OLED display to increase awareness of engine health and emissions. For high emission levels, the system could cut off the vehicle's ignition using a controller. The document reviews different sensor technologies that could be used to monitor the key gases and aims to help reduce environmental pollution from vehicle emissions.
Removal of polluting gasses from the exhaust of combustion engines using mon ...Darren Magee
Magee assisted by Buchannan describes beautifully the process around the Archer reactor. A paper of such importance this describes for the first time cold fission / fusion in use to eliminate greenhouse gasses. This maps out the beginning of a new era in waste, water and sewage treatment accessing an undiscovered source of energy in the process
The document discusses gas sensors and how nanotechnology has influenced their development. It describes how gas sensors can detect harmful gases using various technologies like metal-oxide-semiconductor sensors. Nanotechnology has allowed these sensors to use nano-structured metal oxides, improving their speed, power needs, detection limits and ability to operate at lower temperatures in a more economical way. The document outlines the working principles and applications of gas sensors.
This document describes flame atomic emission spectroscopy. It involves introducing a sample solution into a flame, which excites the atoms and causes them to emit electromagnetic radiation at characteristic wavelengths. This emission spectrum can then be used to qualitatively or quantitatively analyze the elemental composition of the sample. Key components of the instrumentation include a burner assembly to introduce the sample into the flame, wavelength selection devices like monochromators or filters to isolate wavelengths, and detectors like photomultiplier tubes to measure the emission intensities. The intensity of emission depends on factors like temperature, which affects the population of excited states.
Understanding Catalytic Converter Theft:
What is a Catalytic Converter?: Learn about the function of catalytic converters in vehicles and why they are targeted by thieves.
Why are They Stolen?: Discover the valuable metals inside catalytic converters (such as platinum, palladium, and rhodium) that make them attractive to criminals.
Steps to Prevent Catalytic Converter Theft:
Parking Strategies: Tips on where and how to park your vehicle to reduce the risk of theft, such as parking in well-lit areas or secure garages.
Protective Devices: Overview of various anti-theft devices available, including catalytic converter locks, shields, and alarms.
Etching and Marking: The benefits of etching your vehicle’s VIN on the catalytic converter or using a catalytic converter marking kit to make it traceable and less appealing to thieves.
Surveillance and Monitoring: Recommendations for using security cameras and motion-sensor lights to deter thieves.
Statistics and Insights:
Theft Rates by Borough: Analysis of data to determine which borough in NYC experiences the highest rate of catalytic converter thefts.
Recent Trends: Current trends and patterns in catalytic converter thefts to help you stay aware of emerging hotspots and tactics used by thieves.
Benefits of This Presentation:
Awareness: Increase your awareness about catalytic converter theft and its impact on vehicle owners.
Practical Tips: Gain actionable insights and tips to effectively prevent catalytic converter theft.
Local Insights: Understand the specific risks in different NYC boroughs, helping you take targeted preventive measures.
This presentation aims to equip you with the knowledge and tools needed to protect your vehicle from catalytic converter theft, ensuring you are prepared and proactive in safeguarding your property.
Implementing ELDs or Electronic Logging Devices is slowly but surely becoming the norm in fleet management. Why? Well, integrating ELDs and associated connected vehicle solutions like fleet tracking devices lets businesses and their in-house fleet managers reap several benefits. Check out the post below to learn more.
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Kevin Miller, Senior Advisor, Business Models of the Joint Office of Energy and Transportation gave this presentation at the Forth and Electrification Coalition CFI Grant Program - Overview and Technical Assistance webinar on June 12, 2024.
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Charging Fueling & Infrastructure (CFI) Program Resources by Cat PleinForth
Cat Plein, Development & Communications Director of Forth, gave this presentation at the Forth and Electrification Coalition CFI Grant Program - Overview and Technical Assistance webinar on June 12, 2024.
Welcome to ASP Cranes, your trusted partner for crane solutions in Raipur, Chhattisgarh! With years of experience and a commitment to excellence, we offer a comprehensive range of crane services tailored to meet your lifting and material handling needs.
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Expanding Access to Affordable At-Home EV Charging by Vanessa WarheitForth
Vanessa Warheit, Co-Founder of EV Charging for All, gave this presentation at the Forth Addressing The Challenges of Charging at Multi-Family Housing webinar on June 11, 2024.
Expanding Access to Affordable At-Home EV Charging by Vanessa Warheit
oxygen sensor
1. Oxygen Sensor
Kireeti Naga Sharan Bandreddi,
Faculty of Electrical Engineering and Information Technology,
Technical University of Chemnitz,
Chemnitz, Germany
E-mail: kireeti-naga-sharan.bandreddi@s2013.tu-chemnitz.de
Abstract—Advancement of gas sensor technology over the past
few decades has led to significant progress in pollution control
and thereby, to environmental protection. An excellent
example is the control of automobile exhaust emissions, made
possible by the use of oxygen gas sensors. It was developed by
the Robert Bosch GmBH company during the late 1960s under
the supervision of Dr. Günter Bauman. Since early 1970s there
have been sustained studies on oxygen sensors and has led to
development of sensors for various applications with varying
performance characteristics. More recently, for biological and
medical applications, optical oxygen sensors are being to have
an impact. In this report, we focus on different types of oxygen
sensors, design of each sensor, their working principles and
specific applications.
Keywords—Oxygen sensor, Air to fuel ratio, lambda
I. Introduction
An oxygen sensor (or lambda sensor or exhaust
sensor) is an electronic device that measures the proportion
of oxygen in the gas or liquid being analysed. The
original sensing element is made with a thimble-shaped
zirconia ceramic coated on both the exhaust and reference
sides with a thin layer of platinum and comes in both heated
and unheated forms. The planar-style was introduced in the
year 1998 (pioneered by Bosch) and significantly reduced
the mass of ceramic content as well as incorporating the
heater within the ceramic structure. This resulted in a sensor
that started sooner and responded faster. The major
application is to measure the exhaust gas concentration of
oxygen for internal combustion engines in automobiles.
Concern over environmental pollution and health
issues has driven legislation over the past two decades and
significant research and development efforts have been
undertaken to address environmental issues. Worldwide
research in the field of gas sensors for many years has been
driven by the desire to reduce emissions from various
industrial sources. In particular, oxygen sensors have played
a key role in pollution control through automobile engine
management, optimizing industrial boilers, steel, cement
industries, biological and food processing plants and control
of chemical processes. Based on the number of sensors in
operation, the predominant use of oxygen sensors is in the
control of air-fuel mixture in the combustion engine of
automobiles and is an integral part of the ‘on board
diagnostic’ (OBD) of the exhaust emission control system.
The concentration of the partial pressure of the
oxygen in an environment can be determined using different
principles. For high temperature measurements of oxygen,
ceramic-based sensors are most practical. Equilibrium
potential measurements on solid electrolyte-electrode cells
enable oxygen measurement via the Nernst equation. The
sensor output varies logarithmically with oxygen partial
pressures. These sensors provide reproducible, stable and
accurate measurements of even low levels (ppm) of oxygen.
By imposing a diffusion barrier between the test gas flow
and the electrode, the electrolyte-electrode cell can be
operated. Then the current flowing through the cell provides
a measure of oxygen. As such, this sensor does not require
reference oxygen column and can respond linearly with
oxygen concentration. Semiconductor based sensors
measure oxygen via changes in electrical conductance
arising from alteration of defect chemistry by
chemisorptions of oxygen. All of these sensors described
above operate at high temperatures ranging from 300 ⁰C to
1000 ⁰C and can be used in harsh environment.
Monitoring oxygen under ambient conditions and
especially as dissolved oxygen is necessary in medical, food
processing and waste management industries.
A working sensor is typically characterized by
three parameters: sensitivity, selectivity and response time.
Sensitivity is the ability of the sensor to quantitatively
measure the test gas under given conditions. It is governed
by the inherent physical and chemical properties of the
materials used. Selectivity of the sensor is its ability to sense
a particular gas from interference. Response time is the
measure of how quickly the maximum signal change is
achieved with gas concentration changes. In addition,
reversibility, long term stability, size and power
consumption are other factors influencing the overall
performance of the sensor.
II. Exhaust system in an automobile
The exhaust system in an automobile consists of an
exhaust manifold, catalytic converter, resonator and a
muffler connected to a tail pipe. Inside the exhaust manifold,
hot exhaust gases along with sound waves are generated at
the end of exhaust stroke is sent to the exhaust manifold
through the exhaust valve. These sound waves and exhaust
gases pass from exhaust manifold to catalytic converter
through a pipe. Due to the partial combustion, the gases
entering inside the catalytic converter consists of a mixture
of carbon monoxides (CO), unburned hydrocarbons (HC)
and oxides of nitrogen which are harmful to
environment.
Inside the catalytic converter there are two ceramic
blocks with micro ducts consisting of platinum and rhodium
in one block while platinum and palladium in other block,
acting as catalysts. The toxic gas enter into the first ceramic
block and heat up simultaneously. This causes the catalyst to
react with the toxic gases. As the gases enter inside, the
nitrogen molecules are the first to react.
2. The catalyst causes the oxides of nitrogen to reform
into nitrogen and oxygen respectively.
The gas then flows through the micro ducts of the
second ceramic block where it reacts with the platinum and
palladium. Here, the carbon monoxide reacts with oxygen
molecules to form carbon dioxide (CO2).
The unburned hydrocarbons also react with oxygen to form
water and carbon dioxide.
The exhaust gas now becomes less toxic and comes from
catalytic converter having mixture of carbon dioxide,
nitrogen and water vapours. The exhaust gas now becomes
less toxic but consists of sound waves generated by the
engine.
To cancel the noise of these sound waves the gas is
made to flow through the muffler, which consists of
chambers of different sizes. The gases with sound waves
enter the first chamber of the muffler, which has drilled
holes around its surface. Some of the waves come out
through these holes and move back and forth against the
walls of the muffler. As more waves come out through the
holes, the space for movement reduces which causes friction
and ultimately destroys the sound waves.
Sound waves with more intensity pass through the
first chamber and try to enter into the second chamber. Here
the sound waves again collide with the walls and destroy
due to friction. The loudest sound waves make through both
the chambers and enter the Helmholtz resonator. Here the
sound waves hit the walls of the resonator and bounce back,
generating opposite sound wave of same frequency. This
phenomenon causes the sound waves to cancel each other.
Before flowing out through the tail pipe, the gas
and sound waves are made to flow through the third
chamber, where the noise is further reduced due to friction.
Finally, the exhaust gases consisting of less harmful gases
along with considerably low sound waves move out of the
tail pipe into the atmosphere.
III. Application in automotive
Oxygen sensor is located on the exhaust line, one
before the catalytic converter (upstream/pre-cat sensor) and
one after the catalytic converter (downstream/post-cat
sensor). Upstream sensor is used for regulating the fuel
supply that is it monitors the oxygen content of the vehicle’s
exhaust gases and sends a voltage signal to electronic
control unit (ECU). Where as a downstream sensor is placed
on 1996 or newer vehicles to monitor the performance of
catalytic converter and also detects whether the upstream
sensor is still working properly.
High pressure and temperature exhaust gases
leaving the engine cylinder during the exhaust stroke, travel
through the exhaust manifold and come in contact with the
oxygen sensor placed before the catalytic converter. The
sensing element at the front of the sensor consists of a
zirconium dioxide sensing element enclosed within a steel
shell. The sensing element is further connected to platinum
electrodes and wire leads down the line.
Exhaust gas consisting of oxygen molecules, come
in contact with the sensing element after flowing through the
holes on the steel shell. Outside air is made to flow through
the gaps between the connecting cables. This air is then
heated to enable the ions to produce voltage. The difference
in concentration of oxygen molecules in the exhaust gas and
the ambient air drives the oxygen ions from higher to lower
concentration.
Figure 1: Oxygen sensor in a car
Due to the movement of the oxygen ions from one
platinum layer to the other, a potential difference is
generated. A rich mixture surges the voltage approximately
up to 0.9V. On contrary, lean mixture drops the voltage
down to 0.1V.
These voltages signals are fed to electronic control
unit. Thus, the electronic control unit compares it with the
pre-stored standard data to decide whether the mixture is
lean or rich. These calculations are used to manipulate the
air-fuel ratio during the subsequent stroke.
IV. Design of two-step lambda oxygen sensor
Finger-type sensor
Sensor ceramic element with protective tube: The
solid electrolyte is a ceramic element which is impermeable
to gas. It is composed of a mixed oxide of zirconium and
yttrium in the shape of finger. The surfaces have been
provided on both sides with electrodes. The platinum
electrode inside the exhaust pipe, acts like a small catalytic
converter, and treats the exhaust gas catalytically and brings
back to stoichiometric balance (λ=1). In addition, the side
exposed to exhaust gas has a porous, ceramic multilayer to
protect it against contamination erosive damage, mechanical
impact and thermal shocks by metal tube. The sensor’s open
inner chamber facing away from the exhaust gas is
connected to the outside air, which acts as a reference gas.
Sensor with heater element and electric
connections: A ceramic support tube and a disc spring hold
and seal the active, finger-shaped sensor ceramic element in
the sensor housing. A contact element between the support
tube and the active sensor ceramic element provides the
contact between the inner electrode and the connecting
3. cable. By using a metal sealing ring, the outer electrode is
connected to the sensor housing.
Figure 2: Finger type sensor in exhaust pipe
A protective metal sleeve, which at the same time
serves as a support for the disc spring, locates and fixes the
sensor’s complete inner structure. It also protects the sensor
interior against contamination. The connecting cable is
grooved to the contact element which protrudes from the
sensor, and is protected against moisture and mechanical
damage by a temperature resistant cap. It is also equipped
with an electrical heater element. This ensures that the
ceramic element temperature remains sufficiently high, even
at low engine load and thus low exhaust-gas temperature.
This external heating is so quick that the sensor reaches the
operating temperature (350 ⁰C) within a response time of
20...30s and thus ensures low and stable exhaust-gas
emissions.
Planar lambda sensor
In terms of its function, the planar lambda sensor
corresponds to the heated finger-type sensors with a voltage-jump
curve at λ=1. However, on the planar sensor, the solid
electrolyte is comprised of a number of individual laminated
foils stacked one on top of the other. The sensor is protected
against thermal and mechanical influences by a double-walled
protective tube.
Figure 3: Planar lambda sensor
Its shape is like a long stretched-out wafer with
rectangular cross section. The surfaces of the measuring
cells are designed to protect against the erosive effects of the
exhaust. The heater is a wave shaped element containing
noble metal, integrated and insulated in the ceramic wafer
and ensures that the sensor heats up quickly even in the
event of low power input. The reference air passage inside
the sensor operating as a reference gas sensor, has access to
the ambient air. It can therefore compare the residual oxygen
in the reference atmosphere. Thus, the planar sensor voltage
also demonstrates an abrupt change in the area of the
stoichometric composition of air/fuel mixture (λ=1).
V. Method of operation of two-step lambda
sensor
Two-step lambda oxygen sensors operated on the
principle of a galvanic oxygen concentration cell with a
solid electrolyte (Nernst principle). The Nernst equation is
given as follows:
’
Where Us = Sensor voltage, R = Gas constant, T = Absolute
temperature, F = Faraday’s constant, = Partial pressure
of oxygen in the exhaust side and ’ = Partial pressure of
oxygen in the reference side
The ceramic element is conductive for oxygen ions
from a temperature of approximately 350 ⁰C (safe, reliable
operation at > 350 ⁰C). Due to the abrupt change in the
residual-oxygen content on the exhaust-gas side in the range
of λ=1 (e.g., 9*10-15 % vol. for λ = 0.99 and 0.2% vol. for
λ=1.01), the different oxygen content on both sides of the
sensor generates an electrical voltage between the two
boundary layers. This means that the oxygen content in the
exhaust gas can be used as a measure of the air/fuel ratio.
The integrated heater ensures that the sensor functions even
at extremely low exhaust-gas temperatures.
The voltage output by the sensor Us is dependent
on the oxygen content in the exhaust gas. In the case of a
rich mixture (λ < 1), it reaches 800...1000mV, and, in the
case of a lean mixture (λ > 1), it reaches only about 100mV.
The transition from rich to lean occurs at =
450...500mV.
Figure 4: Voltage curve of a two step lambda sensor for
different operating temperatures
The temperature of the ceramic element influences
its ability to conduct the oxygen ions, and thus the shape of
the output-voltage curve as a function of the excess-air
factor λ. In addition, the response time for a voltage change
4. when the mixture composition changes is also strongly
dependent on temperature.
Whereas these response times at ceramic-element
temperatures of below 350 ⁰C are in the seconds range, the
sensor responds at optimum operating temperatures of
around 600 ⁰C in less than 50ms. When an engine is started,
therefore, lambda closed-loop control is deactivated until the
minimum operating temperature of about 350 ⁰C is reached.
During this period the engine is open-loop-controlled.
VI. Design of broad-band lambda sensor
The broad-band lambda sensor is a planar dual-cell
limit-current sensor. It features a measuring cell made of
zirconium-dioxide ceramic , and is a combination of
a Nernst concentration cell (sensor cell which functions in
the same way as a two-step lambda sensor) and an oxygen
pump cell for transporting the oxygen ions. The oxygen
pump cell (Fig. 5, Pos. 8) is arranged in relation to the
Nernst concentration cell (7) in such a way that there is a
10...50μm diffusion gap (6). Here, there are two porous
platinum electrodes: one pump electrode and one Nernst
measuring electrode. The diffusion gap is connected to the
exhaust gas by way of a gas-access passage (10). A porous
diffusion barrier (11) serves to limit the flow of oxygen
molecules from the exhaust gas.
Figure 5: Planar broad band lambda sensor
On the one side, the Nernst concentration cell is
connected to the surrounding atmosphere by a reference-air
passage (5), and on the other, it is connected to the exhaust
gas in the diffusion gap.
The sensor requires control-electronics circuitry to
generate the sensor signal and to regulator the sensor
temperature.
An integrated heater (3) heats the sensor so that it
quickly reaches the operating temperature of 650...900 ⁰C
which is required for a signal that can be evaluated. This
function drastically reduces the influence of the exhaust-gas
temperature on the sensor signal.
VII. Method of operation of broad-band
lambda sensor
The exhaust gas enters the actual measuring chamber
(diffusion gap) of the Nernst concentration cell through the
pump cell’s small gas-access passage. In order that the
excess-air factor λ can be adjusted in the diffusion gap, the
Nernst concentration cell compares the gas in the diffusion
gap with the ambient air in the reference-air passage.
Figure 6: Pump current Ip of a broad band
lambda sensor as a function of the exhaust-gas
2
1
0
-1
-2
-3
excess-air factor λ
0 1 2 3 4 5
Excess-air factor, λ
The complete process proceeds as follows: By
Pump current, Ip
applying the pump voltage UP across the pump cell’s
platinum electrodes, oxygen from the exhaust gas can be
pumped through the diffusion barrier and into or out of the
diffusion gap. With the aid of the Nernst concentration cell,
an electronic circuit in the ECU controls the voltage
across the pump cell in order that the composition of the gas
in the diffusion gap remains constant at λ = 1. If the exhaust
gas is lean, the pump cell pumps the oxygen to the outside
(positive pump current). On the other hand, if the exhaust
gas is rich, the oxygen (due to the decomposition of and
H2O at the exhaust-gas electrode) is pumped from the
surrounding exhaust gas and into the diffusion gap (negative
pump current). At λ = 1, no oxygen needs to be transported,
and the pump current is zero. The pump current is
proportional to the oxygen concentration in the exhaust gas
and is thus a (non-linear) measure of the excess-air factor λ.
VIII. Pros and cons
A new or good working oxygen sensor can have
many advantages, over an automobile with ‘damaged or no’
oxygen sensor they can be as follows:
High signal resolution and low pressure sensitivity
help provide precise engine control.
Integral heater enables faster light-off for early
closed loop operations.
Unique planar element design enhances thermal
shock resistance.
Fast response helps improve fuel economy.
Industry-leading poison-resistant coating helps
achieve better durability.
Pumped air reference prevents air reference
contamination.
Low power consumption reduces the vehicle’s
electrical energy requirements.
Robust construction resists thermal shock without
cracking.
On the other hand a worn-out oxygen sensor or an
automobile with no oxygen sensor can have the
following disadvantages like fuel gets wasted, can cause
engine performance problems like, surging and
hesitating. It is the number one cause of excessive
5. harmful exhaust emissions and lastly, can cause a major
damage to catalytic converter.
IX. Future enhancements
One of the fastest growing industries in the present
world is automotive, which requires a huge demand for
precision, accuracy, fuel economy, safety issues, eco
friendly, best in design, long lasting etc. These are some of
the issues to be considered for developing an automobile to
full fill above requirements in the future using various
available technologies. One of the major issues being,
pollution which has to be reduced, from car to car in this
automotive world. Sensors play a key role in this aspect,
more importantly oxygen sensors, which need further
development day to day. Major issues like less operating
voltage, much lesser response time, reducing the weight of
heater element further, also by implementing various other
sensors in the exhaust path to monitor various other issues
so as to reduce the harmful gases, increasing the life time of
the sensor, reducing the cost, reducing the damage issues of
the sensor that is exposed out in the reference side that is
making it strong enough to with stand heat, water, etc.
X. Conclusion
As per Union of Concerned Scientists (UCS), a
gallon of gas is equal to 24 pounds of global warming
emissions. On the other hand as of United States
Environmental Protection Agency (USEPA), it is 28% of
greenhouse gas emissions are only from automobiles and a
whopping 75% of carbon dioxide emissions come from
automobiles. Previously, the use of planar type sensors has
changed an automobile to more eco-friendly and fuel
efficient type but things changed. Broad band oxygen
sensors revolutionised the entire exhaust system making it
more fuel efficient and less toxic gases. So, at the bottom
line taking the statistics from various organisations
regarding the pollution and the response of using oxygen
sensors among the automobile owners and making it a
compulsory module in the latest automobiles from the
manufacturer seems good in the days ahead.
XI. Acknowledgement
I would like to thank many people at the Chair of
Measurement and Sensor Technologies in Technical
University of Chemnitz who helped me with presentation
and report on oxygen sensors. Many people took time to
share their experience and expertise. Other people helped
me with the presentation on “Oxygen Sensor . I would like
to thank Prof. Dr.-Ing. Olfa Kanoun, Dr.-Ing Thomas
Keutel, Frank Ebert and Dr. Christian Müller for giving me
this opportunity.
XII. References
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[3] Wiley, Bosch Automotive Handbook (7th Edition),
Plochingen: Robert Bosch GmbH, 2007
[4] Wiley, Gasoline-Engine Management (3rd Edition),
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[5] R. Ramamoorthy, P.K Dutta, S.A. Akbar, “Oxygen
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[6] “Oxygen sensor,
http://en.wikipedia.org/wiki/Oxygen_sensor, last update
12/06/2014
[7] “Why clean vehicle,
http://www.ucsusa.org/clean_vehicles/why-clean-cars/
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[8] “Sources of Greenhouse Gas Emissions,
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[10] “Bosch Auto parts – Oxygen Sensor Design,
http://www.boschautoparts.com/OxygenSensors/Pages/Oxy
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[11] “Bosch Auto parts – Lambda Sensors,
http://www.boschautoparts.com/BAP_Technical_Resources
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[12] “Delphi Wide Range Oxygen Sensor,
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[13] “Delphi Wide Range Oxygen Sensor,
http://delphi.com/shared/pdf/ppd/sensors/switching-oxygen-sensors.
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[12] "How does the oxygen sensor in a car work?"
HowStuffWorks.com.
<http://auto.howstuffworks.com/question257.htm>, 24 June
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[13] “How Car Exhaust System Works,
https://www.youtube.com/watch?v=W6dIsC_eGBI,
Published on 08/02/2013
[14] “How Oxygen Sensor Works,
https://www.youtube.com/watch?v=Fl3aD1qJrEg, Published
on 13/08/2013