外文翻译---传感器新技术的发展

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外文翻译---传感器技术的新进展

外文翻译---传感器技术的新进展

附录A英文原文——From X IA W e-i q iang, FAN Shang-chun Chinese Journal of Scientific Instrument Advances in Sensor Technology DevelopmentThe sensor technology is an important technical foundation of the new technological revolution and the information society, is a multidisciplinary science and technology, and is widely regarded as the source of the modern information technology [1].In recent years, sensor technology developmentFast, and made many new developments, in particular, has made a lot of progress in terms of gas sensors, biological sensors, vision sensors [2 - 3].Massachusetts Institute of Chinese scientist Zhang Shuguang research team led by means of a special solution to find the large-scale manufacture of the olfactory receptor [4]; same MIT researchers used gas chromatography - mass spectrometry feelidentify gas molecules, developed a trace toxic gases react strongly miniature sensors [5]; Russian scientists as raw material extracted from a common mushroom mixture, a resonant sensor with a piezoelectric quartz crystal canvery low levels of phenol in the detection of air ingredient Japanese scientists have developed quickly identify influenza virus nanosensors [7], nanotechnology is expected to quickly identify influenza virus, hepatitis B virus, mad cow disease pathogens and pesticide residues and other substances [6];the Autonomous University of Barcelona, Spain, developed a new means;New microfilm DNA analysis sensors [8], this sensor is able to analyze the DNA chain time shortened to a few minutes or a few hours, intelligent instrument and sensor technology, space biology, intelligent sensing technology.Applications, a series of laboratory tests in a paternity test to detect genetically modified food also can determine the genetic toxicity of new drugs; National Institute of Standards and Technology Research Institute to develop an ultra-sensitive micro-nuclear magnetic resonance (NMR) sensor, the micro-sensor andparallel microfluidic channels in a silicon chip on top of this technology to enhance the detection sensitivity of NMR to a new level, with a wide range of application prospects [9] in the chemical analysis.Our sensor technology compared with foreign countries, there is a big gap, but the last two years has also made some progress and breakthroughs, the birth of some new products, some of the major national Model Engineering application.Such as resource ringReality technology in the field of environmental monitoring and environmental risk assessment technology, fast online monitoring technology of Air Pollution Complex key gaseous pollutants and airborne fine particles and ultrafine particles fast online monitoring technology, marine technology collarDomain of marine water pollution parameters online monitoring technology and marine metal contaminants on-site and on-line monitoring techniques.HgCdTeinfrared sensors have been used in China's Fengyun series satellites, oceanic satellites and Shenzhou series flyShip.Beijing University of Aeronautics and Astronautics invented the small precision CMOS celestial sensor technology won the 2008 National Invention and Technology Prize [10].The development of these technologies highlights sensor technology showing toThe high-precision, miniaturization, micro-power consumption and passive, intelligent, high reliability direction of the trend, the following were discussed.The main direction of development of sensor technology to the development of high-precisionAutomated production technology continues to evolve, the requirements of the sensor is also continuously improve the requirements developed with high sensitivity, high accuracy, fast response speed, good interchangeability new sensor to ensure the reliability of production automation.In recent years, the world's major the sensor research institutions using new theories, new methods, new techniques to improve the sensor accuracy achieved outstanding results.American scholars have found a new method to improve the sensitivity of the sensor [11], to take a systematic approach to the various design rules together with a consistent framework to improve the design of the sensor.They compared the traditional planar sensor (p lanar sensor) components with cylindrical single nanotube sensor (cylindrica l sing le-nano tube sensor)Components, the results show the smaller cylindrical sensitivity of the sensor is at least 100 times higher, which is sufficient to prove that the smaller the better the theoretical.University of California at Berkeley and the Berkeley Lab researchers create the world's first fully functional nanotube device, the successful construction of a weighing gold atoms nanoelectromechanical systems (NEMS) [12].This device measured the gold atoms quality for 3125 @ 10 -22 g.The NEMS mass sensor consists of a single carbon nanotube, double wall, with all the electronic properties, and the increase in hardness.The one end of the carbon nanotubes can be freely, while the other end is connected to one electrode, and the distance relative to the electrode is very near.The DC power from the battery or solar cell on the pair of electrodes connected, cause it to some fluctuations in the resonance frequency of vibration.When an atom or molecule is stored above carbon nanotubes, the resonant frequency of this carbon nanotube will therefore the mass of the atoms or molecules to change, similar to the different weight diver would change the resonance frequency of the diving board.American Oak R idge National Laboratory using silicon micro-electromechanical systems (MEMS) sensor detected 515 fg (femtograms) of the substances, and to create a new world record [13].The use of only 2 Lm Length, 50 nm thick silicon cantilever, by an inexpensive diode laser vibration.The researchers believe that the use of MEMS sensors in theory be able to detect any substances.British the Transense company launched a precision level millionth non-contacttorque sensor Torqsense [14].This sensor is based on the principle of surface acoustic wave(SAW),thesizeofonly4mm@********************************* torque of the shaft, the two SAW sensor and the shaft was continuously into / half-bridge 0 structure; When the shaft is subject to torque, a pressure receiving a tensile the consolidated two sensors frequency generating / Difference 0 or /superposition 0 signal to derive the respective torque or temperature signal.Epson Toyocom Corporation developed a? 10 Pa (about one ten thousandth atmospheric pressure) of high accuracy and high resolution of 011 Pa and a volume of 1215 ml, weight is 15 g small crystal absolute pressure sensor [15].Tuning-fork type crystal unit is used in the pressure detecting unit, whereby the oscillation frequency of high stability can be obtained, thus achieving the pressure sensor with high precision and high resolution crystal; on top of this using QMEMS technology developed a new original.pressure sensing structure, to make it possible to have both small and high performance.Taiyo Yuden developed a detection sensitivity of 10 @ -9 (1ppb) gas sensor [16], because of its gas adsorption characteristics, Taiyo Yuden be called / of nanoscale gas sensor 0, and in October 2007show opening / CEATEC JAPAN 20070.The sensor 80Lm @ 500Lm dielectric film is formed on a silicon wafer, using a dielectric film after the adsorbed gas, the resistance value change of the dielectric film, in order to detect the gas.112 development to the miniaturization of various control equipment function more and more, the requirements of the various components of smaller is better, and thus the sensor itself, the volume is as small as possible, which requires a focus on the development of micro-sensors based on new materials and processing technology.French scientist, winner of the 2007 Nobel Prize in Physics Albert # Fil German scientist Peter # Green Berger found / giant magnetoresistance 0 effect [17 - 19], not only can produce more sensitive data read headThe increasingly weak magnetic signals and still be able to be clearly read out and converted into a clear current change.The breakthrough in the technology provides an extremely important technical support for the miniaturization of sensors.Hitachi Metals has developed the world's smallest 3-axis acceleration sensor, external dimensions of 215mm @ 215 mm _AT_ 1mm volume of 6125 mm3 to varistor resin package.The package size smaller than similar products by 30% the volume and weight of 14 mg, 46% lower than similar products, with more than 20,000 gravitational acceleration impact resistance.Japanese scientists have also successfully developed the world's smallest ultra-sensitive tactile sensor, the prospects for a wide range of applications in the field of medical devices.The sensor is embedded in the synthetic resin of approximately 011mm3 a diameter of 1 ~ 10 Lm, long of 300 ~~ 500 Lm, the helical spring-like fine carbon coil element, carbon coil after the contact with the object, will be minor changes in pressure and temperature conversioninto electrical signals.Furthermore, the sensor can also sense / screwed 0, / 0, etc. of friction signal.113 micro-power consumption and passive sensor can not work without power, in the field or in a place far from the grid, often with a battery or solar power, the development of micro-powersensor and passive sensor is an inevitable development direction,In this way, you can saveEnergy and can improve the life of the system.German scientists have developed a sensor, the energy of the fluid (liquid or gas) can have through their own conversion into electricity, which means that the sensor can own / power generation 0, which would greatly facilitate the design and maintenance of the system.The conversion process is carried out in a fixed cavity into electricity, the media fluid (liquid or gas) through the heart as blood flows through here like.Due to the Coanda effect, the flow of fluid is close to the conduit wall; continuous flow generated here periodic pressure fluctuations, to the piezoelectric ceramics, piezoelectric ceramic ultimately by the energy of the fluid is converted into electrical conduction by the feedback member.Generated electricity in the microwatt or milliwatt able to meet the energy demand of the loop running sensor to ensure the sensor reading and outgoing data.British Perpetuum and CAP-XX, Australia developed without battery driven wireless sensor terminal The terminal is equipped with a micro vibration can be converted to energy generators and double-layer capacitor.The vibration of the installation site can be used as energy, power generation, the surplus electric power can be stored in the electric double layer capacitor [23].114 to the intelligent development of increasingly complex with the development of science and technology, the function of the sensor.Its output is no longer a single analog signal, but after the microprocessor processing the digital signal, and some even with a control function.Technology development that the digital signal processor (DSP) will promote the development of many new next-generation products.The technology laboratory R & D of the San Jose Accen ture one is called / 0 of smart dust smart sensing system can automatically monitor and leaf-like objects combustion warning.Once the smart dust sensor point will be near each small dust sprayed into the trees, dust to locate and establish a wireless connection.When spotted possible anomalies detected, it will touch the the nearby dust size device to determine their access to information, and get multiple information from multiple sources, then the sensor will be able to judge a tree dangerous.Once the danger trigger sensor group through its wireless connection to send messages to woodland workers to monitor the sensor network.Ok i recently introduced ultra-small triaxial accelerometer module the ML8950, integrated sensor chip and control IC, the world's thinnest package.Has detected a triaxial accelerometer function can also detect tilt and impact shocks.The controlling IC chip is fitted in the signal amplifying circuit, a control circuit, analog-to-digital converter, and temperature compensation circuit.Furthermore, it is the first with a digital interface triaxial accelerometer module, because it can be directly connected to the CPU, so without the use of analog to digital signal converter device can be embedded in the digital device.115 directly affects the reliability of the sensor to the high reliability electronic device antijamming performance, the development of high reliability, the wide temperaturerange of the sensor will be permanent direction.Improve the temperature range has always been a major issue in the scope of its work, most sensors are - 20 ~ 70e, in the military system requirements Operating temperature -40 ~ 85e range, while cars boiler occasions require sensor temperature requirements are higher, so the development ofpromising emerging materials (such as ceramic) sensor.Honeyw e ll launch LG1237 absolute pressure sensor is an intelligent, accurate, stable measurement of the product within the pressure range of 015 to 1000 Pa, its service life of 25 years or 100, 000 hours.Product - 55e to 125e, the accuracy rate of over? 0103% F1S1, the device will be with a piezoresistive pressure sensor connected with the DSP of the microprocessor, and can withstand the live level acceleration and vibration.Institute of Precision Engineering, Xi'an Jiaotong University successfully developed an anti-shock 2000e instantaneous ultra high temperature silicon isolated high temperature pressure sensor.The sensors in the environment - 30 ~ 250e pressure measurement, pressure measurement to be completed by the of 1000MPa any of the following range, and can withstand the high temperature of 2000e instantaneous impact, to meet the high-temperature, high-pressure, high-frequency response and instantaneous temperature impact and other harsh environmentspressure measurement.The sensor is an effective solution to the technical problems of sensor failure pressure measurement and instantaneous temperature impact in the field of China's aerospace, petrochemical, automotive and other high-temperature environment.The development of biosensorsIn recent years, with the development of biotechnology, bio-sensor has also been a lot of development.And attaches great importance to the food industry, environmental monitoring, fermentation industry, medicine and a wide range of applications, such as for the detection of food ingredients, food additives, harmful toxins and food freshness [28 -31].Environmental pollutants, continuous, rapid, on-line monitoring of foreign subcellular lipids fixed made of cellulose acetate membrane and oxygen electrode amperometric biosensor detection of acid rain acid mist sample solution.Widely used microbial sensors take advantage of this electrochemical sensors can be of the number of microbial cells as an effective measurement tool, a continuous, on-line determination of the cell concentration in the fermentation industry.Microbial sensor is not only used in clinical medicine, and is also used in military medicine, through timely and rapid detection of bacteria, viruses, and biological weapons defense.The past two years, China has invested in biosensor research on a lot of manpower and resources, made some pretty good results.For example, successfully developed / protein chip biosensor system 0 and its practical prototype provides a novel label-free protein analysis technology.The water-soluble conjugated polymer is used as a new fluorescent probes, the design of a series of conjugated polymer-based biosensor system.The use of fluorescence resonance energy transfer principle, the development of novel high sensitivity based on the conjugated polymer spent hydrogen peroxide and glucose sensing system.Conjugated through the regulation ofthe electron transfer process of the polymeric system, to achieve a sensitive detection of the nitroxide free radicals and antioxidants.117 quantum mechanics and sensor technology, the development of quantum mechanics provides a theoretical basis for the development of modern science and technology.Development of quantum effects sensitive a measurement of the quantum-sensitive devices, such as resonant tunneling diodes, quantum well lasers and quantum interference components, with high-speed (increased 1,000-fold) than the sensitive electronic devices speed, low-power (more sensitive than electronicdevices reduce energy consumption by 1000 times), efficient, highly integrated, reliable and economic advantages.Therefore, the development of nanoelectronics, may lead to a new revolution in sensor technology and sensor technology to a new stage of development.2 domestic sensor gapIn recent years, China's sensor industry has made great strides, and has formed the basis of a certain industry, but there is still a wide gap compared with developed countries. Scientific research and development behind the international level from 5 to 10 years, 10 to 15 years behind the large-scale production technology. China's chemical industry, the security monitoring sensor market, almost all foreign enterprises occupied. Sensors for military, aerospace and other purposes, the foreign country is an embargo. The level of development of the sensor behind a serious impediment to the development of China's automobile, petrochemical, aerospace and other industries. At present, China has yielded few results of independent intellectual property rights of innovative research results to industrial conversion speed is slow, inefficient, and achieved significant social and economic benefits of the project less; able to represent the national level, but also to achieve large-scale production of small enterprises, high-grade fewer products, low market share; big gap between production technology and equipment from the international level; overall in the tracking state. Sensor devices and systems the comprehensive technical level of China's independent innovation capability is low, sensitive materials, integrated design and manufacturing, industrial design, testing and calibration than backward. Gap with foreign countries mainly in: Device varieties, mainly dependent on imports of high-end products; lower level of automation, intelligent; modular, standardized, low degree of integration; poor stability, reliability is low; Low cost the market less competitive.3 countermeasures and suggestionsAccording to the current situation of the development of sensor technology at home and abroad, our gaps, combined with the needs and priorities of China's science and technology, social and economic development strategy, to give overall consideration to the sensor technology, basic research, applied basic research and applied research. Basic research is mainly focused on sensor mechanism of, from a theoretical point of view to solve a number of key technologies of sensor development, provide important theoretical basis for the study of the sensor. Application of basic research on the basis of the basic research, focusing on key technologies provide important technical support for the sensor market process transformation to the theoretical and experimental prototype. In the sensor applied research, the mainexisting, after the application of the basic research stage proved to be more reliable and mature technology into the application stage of the market-oriented products.For our future sensor development countermeasures, including the following aspects:1) the planning of the national level from the level of national development, the future direction of development of the sensor planning, the plan should focus on the development of a new type of high-precision, low power consumption, miniaturization and miniaturized sensors. Note that the combination of production, learning and research.2) between different industries sensors complement each other and promote each sensor as an information access means in different industries have different characteristics and needs. Similar sensor technology for different industries. Should support complementary advantages between the various sectors, including joint research on common technology, craftsmanship help each other, to form a common development of various industries, thus contributing to the sensorVigorously develop technology.3) vigorously promote the construction and development of the sensor research base, to develop sensor senior professionals to encourage the sensor research leading to the national laboratory, the joint ministerial key laboratories, Key Laboratory of the industry and universities Key Laboratory, the formation of a system national the sensor research base group to provide technical support for the development of the sensor. Meanwhile, laboratory and trained expertise of a number of sensors, provide important protection of personnel for the development of sensor technology research areas.4) To change from passive to active, actively develop high-performance sensor in the the sensor research process to avoid simply copying foreign technology. Sensing technology trends, to carry out a prospective study to break through the bottleneck problem, a technology with independent intellectual property rights, to break down foreignTechnological monopoly, in a place on the international.Development of new sensor new sensor, generally should include: a new principle, fill sensor Blank, biomimetic sensors and other aspects. They are interrelated. The working mechanism of the sensor is based on a variety of effects, and the law of which inspire people to further explore the sensitive functional materials with new effects and novel physical properties sensor device developed new principle, which is the development of high-performance, multi-function, important way of low-cost, miniaturized sensors. Structured sensor developed earlier matures. Complex structure type sensor, the general structure it, the volume is too large, the prices are high. Type sensors of the physical properties of roughly contrast, has many attractive advantages, coupled with past development is not enough. Countries in the world in terms of physical properties sensor invest a lot of manpower and material resources to strengthen research, thus making it a noteworthy developments. The various effects of quantum mechanics developed low sensitivity threshold sensor usedto detect weak signals, the development of one of the new trends. Integrated, multifunctional, integrated intelligent sensor includes two definitions, and one multi-element of the same functions in parallel, about a single sensing element of the same type with integrated technology are arranged on the same plane, aligned in one dimension This is the case for a linear sensor, a CCD image sensor. Another definition of integrated multi-functional integration, upcoming sensor zoom, computing, and temperature compensation, link integration, assembled into a single device. With the development of integrated technologies, various types of hybrid and monolithic integrated pressure sensors have appeared, some of them have become a commodity. Integrated piezoresistive, capacitive pressure sensor, and other types of integrated piezoresistive sensors rapid development and wide application. Sensor multifunction is one of the development. The typical example of the so-called multi-functional monolithic silicon, an American University Sensor Research and Development Center developed a multi-axis force sensor can measure three line speed, of three centrifugal acceleration (angular velocity) and three angular acceleration. The main element is mounted on one substrate by four properly designed cantilever consisting of monolithic silicon structures, 9 are correctly arranged in the respective cantilever piezoresistive sensitive components. Multifunctional not only can reduce production costs, reduce the volume, and can effectively improve the stability of the sensor, reliability and other performance indicators. Integrate a plurality of different functions of the sensing element and integrated processing and evaluation of the results of measurement of these parameters, in addition to measurement of a variety of parameters can be performed simultaneously, but also reflects the overall status of the system under test.From the above it can be seen, integrated solid-state sensor brings many new opportunities, it is also the basis of multi-functional. Combination of sensor and microprocessor, the detection function also has information processing, logical judgment, self-diagnostics, and artificial intelligence of "thinking" it is called intelligent sensors. By means of a semiconductor integrated sensor portion signal pre-processing circuit, the input and output interfaces, microprocessor production on the same chip, large-scale integrated intelligent sensor. Smart sensor is the product of the combination of sensor technology and LSI technology, its implementation will depend on the improvement and development of the sensing technology and semiconductor integrated process level. Such sensors have multi-energy, high-performance, small size, suitable for mass production and ease of use, and can say with certainty, is one of the most important direction sensor.The development of new materials, sensor materials is an important foundation of the sensor technology, sensor technology upgrades support. With the advances in materials science, sensor technology has matured, more and more of its kind, In addition to early use of semiconductor materials, ceramic materials, optical fiber, as well as the development of superconducting materials, the development of the sensor provides a material basis. For example, according to many semiconductor materials silicon substrate easy miniaturization, integration, multi-functional, intelligent, and semiconductor optical heat detectors with high sensitivity, high accuracy, non-contactsexual characteristics, the development of infrared sensors, laser sensors modern sensors, fiber optic sensors, etc.; in the sensitive material, a ceramic material, organic material quickly, different formulations can be used mixed raw material and precision deployment of chemical constituents based on, after the precision molding sintering, to obtain one or a certain types of gas-sensitive material having an identification function, is used to produce a new gas sensor. In addition, the organic polymer sensitive materials is of great concern in recent years new sensitive materials with potential applications, the sensor can be made of the thermistor, photosensitive, gas sensing, humidity, force-sensitive ion-sensitive biological Min et al. Sensor technology continues to evolve, but also to promote the development of newer materials, such as nano materials.U.S. NRC has developed a nano ZrO2 gas sensor, and control of motor vehicle exhaust emissions, cleaning up the environment effect good, relatively broad application prospects. As a result of the production of nanomaterials sensor, has a huge interface can provide a lot of gas channel, and the on-resistance is small, is conducive to the development of miniaturized sensor to the birth of more new material With the continuous advancement of science and technology . Adoption of new technology in the development of new sensors, is inseparable from the adoption of new technology. Within the meaning of the new technology is very broad, and here mainly refers to the development of emerging sensor contact a particularly close microfabrication technology. This technique, also known as micro-machining technology, With the IC process development, it is the ion beam, electron beam, molecular beam, a laser beam, and chemical etching for microelectronics processing techniques in recent years, has been the more more used in the sensor field, such as sputtering, vapor deposition, plasma etching, chemical gas deposition (CVD), epitaxy, diffusion, etching, lithography, etc., so far, a large number of sensors made by the process described above reported at home and abroad. Smart materials smart materials refers to the physical, chemical, mechanical, electrical, and other parameters of the design and control of materials, develop biological material characteristics or superior to biological material properties of artificial materials. Some people think that the material has the following functions can be called smart materials: a judgment on the environment can be adaptive function; possess self-diagnostic function; possess self-healing capabilities; function with self-reinforced (or time base). The most prominent feature of the biological material with time base function, this differential sensor characteristics and its variational sensitive.Conversely, the long-term in a particular environment and get used to this environment, the sensitivity decreased. In general, it can adjust its sensitivity to adapt to the environment. In addition to the biological material, most notably smart material is a shape memory alloy, shape memory ceramics and shape memory polymer. The smart material exploration work has just begun, I believe the near future there will be a lot of development.。

传感器——通信电子工程类中英文翻译、外文翻译

传感器——通信电子工程类中英文翻译、外文翻译

What is a smart sensorOne of the biggest advances in automation has been the development and spread of smart sensors. But what exactly is a "smart" sensor? Experts from six sensor manufacturers define this term.A good working "smart sensor" definition comes from Tom Griffiths, product manager, Honeywell Industrial Measurement and Control. Smart sensors, he says, are "sensors and instrument packages that are microprocessor driven and include features such as communication capability and on-board diagnostics that provide information to a monitoring system and/or operator to increase operational efficiency and reduce maintenance costs."No failure to communicate"The benefit of the smart sensor," says Bill Black, controllers product manager at GE Fanuc Automation, "is the wealth of information that can be gathered from the process to reduce downtime and improve quality." David Edeal, Temposonics product manager, MTS Sensors, expands on that: "The basic premise of distributed intelligence," he says, is that "complete knowledge of a system, subsystem, or component's state at the right place and time enables the ability to make 'optimal' process control decisions."Adds John Keating, product marketing manager for the Checker machine vision unit at Cognex, "For a (machine vision) sensor to really be 'smart,' it should not require the user to understand machine vision."A smart sensor must communicate. "At the most basic level, an 'intelligent' sensor has the ability to communicate information beyond the basic feedback signals that are derived from its application." saysEdeal. This can be a HART signal superimposed on a standard 4-20 mA process output, a bus system, or wireless arrangement. A growing factor in this area is IEEE 1451, a family of smart transducer interface standards intended to give plug-and-play functionality to sensors from different makers.Diagnose, programSmart sensors can self-monitor for any aspect of their operation, including "photo eye dirty, out of tolerance, or failed switch," says GE Fanuc's Black. Add to this, says Helge Hornis, intelligent systems manager, Pepperl+Fuchs, "coil monitoring functions, target out of range, or target too close." It may also compensate for changes in operating conditions. "A 'smart' sensor," says Dan Armentrout, strategic creative director, Omron Electronics LLC, "must monitor itself and its surroundings and then make a decision to compensate for the changes automatically or alert someone for needed attention."Many smart sensors can be re-ranged in the field, offering "settable parameters that allow users to substitute several 'standard' sensors," says Hornis. "For example, typically sensors are ordered to be normally open (NO) or normally closed (NC). An intelligent sensor can be configured to be either one of these kinds."Intelligent sensors have numerous advantages. As the cost of embedded computing power continues to decrease, "smart" devices will be used in more applications. Internal diagnostics alone can recover the investment quickly by helping avoid costly downtime.Sensors: Getting into PositionAs the saying goes, 'No matter where you go, there you are.' Still, most applications require a bit more precision and repeatability than that, so here's advice on how to select and locate position sensors.The article contains online extra material.What's the right position sensor for a particular application? It depends on required precision, repeatability, speed, budget, connectivity, conditions, and location, among other factors. You can bet that taking the right measurement is the first step to closing the loop on any successful application.Sensor technologies that can detect position are nearly as diverse as applications in providing feedback for machine control and other uses. Spatial possibilities are linear, area, rotational, andthree-dimensional. In some applications, they're used in combination. Sensing elements are equally diverse.Ken Brey, technical director, DMC Inc., a Chicago-based system integrator, outlined some the following position-sensing options.Think digitallyFor digital position feedback:∙Incremental encoders are supported by all motion controllers; come in rotary and linear varieties and in many resolutions; are simulated by many other devices; and require a homing process to reference the machine to a physical marker, and when power is turned off.∙Absolute encoders are natively supported by fewer motion controllers; can be used by all controllers that have sufficient available digital inputs; report a complete position within theirrange (typically one revolution); and do not require homing.∙Resolvers are more immune to high-level noise in welding applications; come standard on some larger motors; simulate incremental encoders when used with appropriate servo amps; and can simulate absolute encoders with some servo amps.∙Dual-encoder feedback, generally under-used, is natively supported by most motion controllers; uses one encoder attached to the motor and another attached directly to the load; and is beneficial when the mechanical connection between motor and load is flexible or can slip.∙Vision systems , used widely for inspection, can also be used for position feedback. Such systems locate objects in multiple dimensions, typically X, Y, and rotation; frequently find parts ona conveyor; and are increasing in speed and simplicity.A metal rolling, stamping, and cut-off application provides an example of dual-encoder feedback use, Brey says. 'It required rapid and accurate indexing of material through a roll mill for a stamping process. The roll mill creates an inconsistent amount of material stretch and roller slip,' Brey explains.'By using the encoder on the outgoing material as position feedback and the motor resolver as velocity feedback in a dual-loop configuration, the system was tuned stable and a single index move provided an accurate index length. It was much faster and more accurate than making a primary move, measuring the error, then having to make a second correction move,' he says.Creative, economicalSam Hammond, chief engineer, Innoventor, a St. Louis, MO-area system integrator, suggests that the application's purpose should guide selection of position sensors; measurements and feedback don't have to be complex. 'Creative implementations can provide simple, economical solutions,' he says. For instance, for sequencing, proximity sensors serve well in many instances.Recent sensor applications include the AGV mentioned in lead image and the following.∙In a machine to apply the top seals to tea containers, proximity and through-beam sensors locate incoming packages. National Instruments vision system images are processed to find location ofa bar code on a pre-applied label, and then give appropriate motorcommands to achieve the desired position (rotation) setting to apply one of 125 label types. Two types of position sensors were used. One was a simple inductive proximity sensor, used to monitor machine status to ensure various motion components were in the right position for motion to occur. The camera also served as a position sensor, chosen because of its multi purpose use, feature location, and ability to read bar codes.∙ A progressive-die stamping machine operates in closed loop. A linear output proximity sensor provides control feedback for optimizing die operation; a servo motor adjusts die position in the bend stage. A linear proximity sensor was selected to give a dimensional readout from the metal stamping operation; data are used in a closed-loop control system.∙Part inspection uses a laser distance measurement device to determine surface flatness. Sensor measures deviation in return beams, indicating different surface attributes to 10 microns insize. An encoder wouldn't have worked because distance was more thana meter. Laser measurement was the technology chosen because it hadvery high spatial resolution, did not require surface contact, and had a very high distance resolution.An automotive key and lock assembly system uses a proximity sensor for detecting a cap in the ready position. A laser profile sensor applied with a robot measures the key profile.What to use, where?Sensor manufacturers agree that matching advantages inherent to certain position sensing technologies can help various applications.David Edeal, product marketing manager, MTS Sensors Div., says, for harsh factory automation environments, 'the most significant factors even above speed and accuracy in customer's minds are product durability and reliability. Therefore, products with inherently non-contact sensing technologies (inductive, magnetostrictive, laser, etc.) have a significant advantage over those that rely on physical contact (resistive, cable extension, etc.)'Other important factors, Edeal says, are product range of use and application flexibility. 'In other words, technologies that can accommodate significant variations in stroke range, environmental conditions, and can provide a wide range of interface options are of great value to customers who would prefer to avoid sourcing a large variety of sensor types. All technologies are inherently limited with respect to these requirements, which is why there are so many options.'Edeal suggest that higher cost of fitting some technologies to a certain application creates a limitation, such as with linear variabledifferential transformers. 'For example, LVDTs with stroke lengths longer than 12 inches are rare because of the larger product envelope (about twice the stroke length) and higher material and manufacturing costs. On the other hand, magnetostrictive sensing technology has always required conditioning electronics. With the advent of microelectronics and the use of ASICs, we have progressed to a point where, today, a wide range of programmable output types (such as analog, encoder, and fieldbus) are available in the same compact package. Key for sensor manufacturers is to push the envelope to extend the range of use (advantages) while minimizing the limitations (disadvantages) of their technologies.'Listen to your appDifferent sensor types offer distinct advantages for various uses, agrees Tom Corbett, product manager, Pepperl+Fuchs. 'Sometimes the application itself is the deciding factor on which mode of sensing is required. For example, a machine surface or conveyor belt within the sensing area could mean the difference between using a standard diffused mode sensor, and using a diffused mode sensor with background suppression. While standard diffused mode models are not able to ignore such background objects, background suppression models evaluate light differently to differentiate between the target surface and background surfaces.'Similarly, Corbett continues, 'a shiny target in a retro-reflective application may require use of a polarized retro-reflective model sensor. Whereas a standard retro-reflective sensor could falsely trigger when presented with a shiny target, a polarized retro-reflective model uses a polarizing filter to distinguish the shiny target from the reflector.'MTS' Edeal says, 'Each technology has ideal applications, which tend to magnify its advantages and minimize its disadvantages. For example, inthe wood products industry, where high precision; varied stroke ranges; and immunity to high shock and vibration, electromagnetic interference, and temperature fluxuations are critical, magnetostrictive position sensors are the primary linear feedback option. Likewise, rotary optical encoders are an ideal fit for motor feedback because of their packaging, response speed, accuracy, durability, and noise immunity. When applied correctly, linear position sensors can help designers to ensure optimum machine productivity over the long haul.'Thinking broadly first, then more narrowly, is often the best way to design sensors into a system. Edeal says, 'Sensor specifications should be developed by starting from the machine/system-level requirements and working back toward the subsystem, and finally component level. This is typically done, but what often happens is that some system-level specifications are not properly or completely translated back to component requirements (not that this is a trivial undertaking). For example, how machine operation might create unique or additional environmental challenges (temperature, vibration, etc.) may not be clear without in-depth analysis or past experience. This can result in an under-specified sensor in the worst situation or alternatively an over-specified product where conservative estimates are applied.'Open or closedEarly in design, those involved need to decide if the architecture will be open-loop or closed-loop. Paul Ruland, product manager, AutomationDirect, says, 'Cost and performance are generally the two main criteria used to decide between open-loop or closed-loop control in electromechanical positioning systems. Open-loop controls, such as stepping systems, can often be extremely reliable and accurate when properly sized for the system. The burden of tuning a closed-loop systemprior to operation is not required here, which inherently makes it easy to apply. Both types can usually be controlled by the same motion controller. A NEMA 23 stepping motor with micro-stepping drive is now available for as little as $188, compared to an equivalent servo system at about $700.'Edeal suggests, 'Control systems are created to automate processes and there are many good examples of high-performance control systems that require little if any feedback. However, where structural system (plant) or input (demand or disturbance) changes occur, feedback is necessary to manage unanticipated changes. On the process side, accuracy—both static and dynamic—is important for end product quality, and system stability and repeatability (robustness) are important for machine productivity.'For example,' Edeal says, 'in a machining or injection molding application, the tool, mold or ram position feedback is critical to the final dimension of the fabricated part. With rare exceptions, dimensional accuracy of the part will never surpass that of the position sensor. Similarly, bandwidth (response speed) of the sensor may, along with response limitations of the actuators, limit production rates.'Finally, a sensor that is only accurate over a narrow range of operating conditions will not be sufficient in these types of environments where high shock and vibration and dramatic temperature variations are common.'The latestWhat are the latest position sensing technologies to apply to manufacturing and machining processes and why?Ruland says, 'Some of the latest developments in positioning technologies for manufacturing applications can be found in even the simplest ofdevices, such as new lower-cost proximity switches. Many of these prox devices are now available for as little as $20 and in much smaller form factors, down to 3 mm diameter. Some specialty models are also available with increased response frequencies up to 20 kHz. Where mounting difficulties and cost of an encoder are sometimes impractical, proximity switches provide an attractive alternative; many position control applications can benefit from increased performance, smaller package size, and lower purchase price and installation cost.'Corbett concurs. 'Photoelectric sensors are getting smaller, more durable, and flexible, and are packed with more standard features than ever before. Some new photoelectrics are about half the size of conventional cylindrical housings and feature welded housings compared with standard glued housings. Such features are very desirable in manufacturing and machining applications where space is critical and durability is a must. And more flexible connectivity and mounting options—side mount or snout mount are available from the same product—allow users to adapt a standard sensor to their machine, rather than vice versa.'Another simple innovation, Corbett says, is use of highly visible,360-degree LED that clearly display status information from any point of view. 'Such enhanced LED indicates overload and marginal excess gain, in addition to power and output. Such sensors offer adjustable sensitivity as standard, but are available with optional tamperproof housings to prevent unauthorized adjustments.'Photoelectric SensorsPhotoelectric sensors are typically available in at least nine or more sensing modes, use two light sources, are encapsulated in three categories of package sizes, offer five or more sensing ranges, and can be purchasedin various combinations of mounting styles, outputs, and operating voltages. It creates a bewildering array of sensor possibilities and a catalog full of options.This plethora of choices can be narrowed in two ways: The first has to do with the object being sensed. Second involves the sensor's environment.Boxed inThe first question to ask is: What is the sensor supposed to detect? "Are we doing bottles? Or are we detecting cardboard boxes?" says Greg Knutson, a senior applications engineer with sensor manufacturer Banner Engineering.Optical properties and physical distances will determine which sensing mode and what light source work best. In the case of uniformly colored boxes, for example, it might be possible to use an inexpensive diffuse sensor, which reflects light from the box.The same solution, however, can't be used when the boxes are multicolored and thus differ in reflectivity. In that case, the best solution might be an opposed or retroreflective mode sensor. Here, the system works by blocking a beam. When a box is in position, the beam is interrupted and the box detected. Without transparent boxes, the technique should yield reliable results. Several sensors could gauge boxes of different heights.Distance plays a role in selecting the light source, which can either be an LED or a laser. LED is less expensive. However, because LED are a more diffuse light source, they are better suited for shorter distances. A laser can be focused on a spot, yielding a beam that can reach long distances. Tight focus can also be important when small features have tobe sensed. If a small feature has to be spotted from several feet, it may be necessary to use a laser.Laser sensors used to cost many times more than LED. That differential has dropped with the plummeting price of laser diodes. There's still a premium for using a laser, but it's not as large as in the past.Environmental challengesOperating environment is the other primary determining factor in choosing a sensor. Some industries, such food and automotive, tend to be messy, dangerous, or both. In the case of food processing, humidity can be high and a lot of fluids can be present. Automotive manufacturing sites that process engines and other components may include grit, lubricants, and coolants. In such situations, the sensor's environmental rating is of concern. If the sensor can't handle dirt, then it can't be used. Such considerations also impact the sensing range needed because it may be necessary to station the sensor out of harm's way and at a greater distance than would otherwise be desirable. Active alarming and notification may be useful if lens gets dirty and signal degrades.Similar environmental issues apply to the sensor's size, which can range from smaller than a finger to something larger than an open hand. A smaller sensor can be more expensive than a larger one because it costs more to pack everything into a small space. Smaller sensors also have a smaller area to collect light and therefore tend to have less range and reduced optical performance. Those drawbacks have to be balanced against a smaller size being a better fit for the amount of physical space available.Sensors used in semiconductor clean room equipment, for example, don't face harsh environmental conditions, but do have to operate in tight spaces. Sensing distances typically run a few inches, thus the sensorstend to be small. They also often make use of fiber optics to bring light into and out of the area where changes are being detected.Mounting, pricingAnother factor to consider is the mounting system. Frequently, sensors must be mechanically protected with shrouds and other means. Such mechanical and optical protection can cost more than the sensor itself—a consideration for the buying process. If vendors have flexible mounting systems and a protective mounting arrangement for sensors, the products could be easier to implement and last longer.List prices for standard photoelectric sensors range from $50 or so to about $100.Laser and specialty photoelectric sensors cost between $150 and $500. Features such as a low-grade housing, standard optical performance, and limited or no external adjustments characterize the lower ends of each category. The higher end will have a high-grade housing, such as stainless steel or aluminum, high optical performance, and be adjustable in terms of gain or allow timing and other options. Low-end products are suitable for general applications, while those at the higher end may offer application-specific operation at high speed, high temperature, or in explosive environments.Finally, keep in mind that one sensing technology may not meet all of the needs of an application. And if needs change, a completely different sensor technology may be required. Having to switch to a new approach can be made simpler if a vendor offers multiple technologies in the same housing and mounting footprint, notes Ed Myers, product manager at sensor manufacturer Pepperl+Fuchs. If that's the case, then one technology can be more easily swapped out for another as needs change.译文什么是智能传感器自动化领域所取得的一项最大进展就是智能传感器的发展与广泛使用。

传感器技术论文中英文对照资料外文翻译文献

传感器技术论文中英文对照资料外文翻译文献

传感器技术论文中英文对照资料外文翻译文献Development of New Sensor TechnologiesSensors are devices that can convert physical。

chemical。

logical quantities。

etc。

into electrical signals。

The output signals can take different forms。

such as voltage。

current。

frequency。

pulse。

etc。

and can meet the requirements of n n。

processing。

recording。

display。

and control。

They are indispensable components in automatic n systems and automatic control systems。

If computers are compared to brains。

then sensors are like the five senses。

Sensors can correctly sense the measured quantity and convert it into a corresponding output。

playing a decisive role in the quality of the system。

The higher the degree of n。

the higher the requirements for sensors。

In today's n age。

the n industry includes three parts: sensing technology。

n technology。

and computer technology。

热电偶温度传感器中英文对照外文翻译文献

热电偶温度传感器中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)外文翻译:Thermocouple Temperatur sensorIntroduction to ThermocouplesThe thermocouple is one of the simplest of all sensors. It consists of two wires of dissimilar metals joined near the measurement point. The output is a small voltage measured between the two wires.While appealingly simple in concept, the theory behind the thermocouple is subtle, the basics of which need to be understood for the most effective use of the sensor.Thermocouple theoryA thermocouple circuit has at least two junctions: the measurement junction and a reference junction. Typically, the reference junction is created where the two wires connect to the measuring device. This second junction it is really two junctions: one for each of the two wires, but because they are assumed to be at the same temperature (isothermal) they are considered as one (thermal) junction. It is the point where the metals change - from the thermocouple metals to what ever metals are used in the measuring device - typically copper.The output voltage is related to the temperature difference between the measurement and the reference junctions. This is phenomena is known as the Seebeck effect. (See the Thermocouple Calculator to get a feel for the magnitude of the Seebeck voltage). The Seebeck effect generates a small voltage along the length of a wire, and is greatest where the temperature gradient is greatest. If the circuit is of wire of identical material, then they will generate identical but opposite Seebeck voltages which will cancel. However, if the wire metals are different the Seebeck voltages will be different and will not cancel.In practice the Seebeck voltage is made up of two components: the Peltiervoltage generated at the junctions, plus the Thomson voltage generated in the wires by the temperature gradient.The Peltier voltage is proportional to the temperature of each junction while the Thomson voltage is proportional to the square of the temperature difference between the two junctions. It is the Thomson voltage that accounts for most of the observed voltage and non-linearity in thermocouple response.Each thermocouple type has its characteristic Seebeck voltage curve. The curve is dependent on the metals, their purity, their homogeneity and their crystal structure. In the case of alloys, the ratio of constituents and their distribution in the wire is also important. These potential inhomogeneous characteristics of metal are why thick wire thermocouples can be more accurate in high temperature applications, when the thermocouple metals and their impurities become more mobile by diffusion.The practical considerations of thermocouplesThe above theory of thermocouple operation has important practical implications that are well worth understanding:1. A third metal may be introduced into a thermocouple circuit and have no impact, provided that both ends are at the same temperature. This means that the thermocouple measurement junction may be soldered, brazed or welded without affecting the thermocouple's calibration, as long as there is no net temperature gradient along the third metal.Further, if the measuring circuit metal (usually copper) is different to that of the thermocouple, then provided the temperature of the two connecting terminals is the same and known, the reading will not be affected by the presence of copper.2. The thermocouple's output is generated by the temperature gradient along the wires and not at the junctions as is commonly believed. Therefore it is important that the quality of the wire be maintained where temperature gradients exists. Wire quality can be compromised by contamination from its operating environment and the insulating material. For temperatures below 400°C, contamination of insulated wires is generally not a problem. At temperatures above 1000°C, the choice of insulationand sheath materials, as well as the wire thickness, become critical to the calibration stability of the thermocouple.The fact that a thermocouple's output is not generated at the junction should redirect attention to other potential problem areas.3. The voltage generated by a thermocouple is a function of the temperature difference between the measurement and reference junctions. Traditionally the reference junction was held at 0°C by an ice bath:The ice bath is now considered impractical and is replace by a reference junction compensation arrangement. This can be accomplished by measuring the reference junction temperature with an alternate temperature sensor (typically an RTD or thermistor) and applying a correcting voltage to the measured thermocouple voltage before scaling to temperature.The correction can be done electrically in hardware or mathematically in software. The software method is preferred as it is universal to all thermocouple types (provided the characteristics are known) and it allows for the correction of the small non-linearity over the reference temperature range.4. The low-level output from thermocouples (typically 50mV full scale) requires that care be taken to avoid electrical interference from motors, power cable, transformers and radio signal pickup. Twisting the thermocouple wire pair (say 1 twist per 10 cm) can greatly reduce magnetic field pickup. Using shielded cable or running wires in metal conduit can reduce electric field pickup. The measuring device should provide signal filtering, either in hardware or by software, with strong rejection of the line frequency (50/60 Hz) and its harmonics.5. The operating environment of the thermocouple needs to be considered. Exposure to oxidizing or reducing atmospheres at high temperature can significantly degrade some thermocouples. Thermocouples containing rhodium (B,R and S types) are not suitable under neutron radiation.The advantages and disadvantages of thermocouplesBecause of their physical characteristics, thermocouples are the preferred methodof temperature measurement in many applications. They can be very rugged, are immune to shock and vibration, are useful over a wide temperature range, are simple to manufactured, require no excitation power, there is no self heating and they can be made very small. No other temperature sensor provides this degree of versatility.Thermocouples are wonderful sensors to experiment with because of their robustness, wide temperature range and unique properties.On the down side, the thermocouple produces a relative low output signal that is non-linear. These characteristics require a sensitive and stable measuring device that is able provide reference junction compensation and linearization.Also the low signal level demands that a higher level of care be taken when installing to minimise potential noise sources.The measuring hardware requires good noise rejection capability. Ground loops can be a problem with non-isolated systems, unless the common mode range and rejection is adequate.Types of thermocoupleAbout 13 'standard' thermocouple types are commonly used. Eight have been given an internationally recognised letter type designators. The letter type designator refers to the emf table, not the composition of the metals - so any thermocouple that matches the emf table within the defined tolerances may receive that table's letter designator.Some of the non-recognised thermocouples may excel in particular niche applications and have gained a degree of acceptance for this reason, as well as due to effective marketing by the alloy manufacturer. Some of these have been given letter type designators by their manufacturers that have been partially accepted by industry.Each thermocouple type has characteristics that can be matched to applications. Industry generally prefers K and N types because of their suitability to high temperatures, while others often prefer the T type due to its sensitivity, low cost and ease of use.A table of standard thermocouple types is presented below. The table also showsthe temperature range for extension grade wire in brackets.Accuracy of thermocouplesThermocouples will function over a wide temperature range - from near absolute zero to their melting point, however they are normally only characterized over their stable range. Thermocouple accuracy is a difficult subject due to a range of factors. In principal and in practice a thermocouple can achieve excellent results (that is, significantly better than the above table indicates) if calibrated, used well below its nominal upper temperature limit and if protected from harsh atmospheres. At higher temperatures it is often better to use a heavier gauge of wire in order to maintain stability (Wire Gauge below).As mentioned previously, the temperature and voltage scales were redefined in 1990. The eight main thermocouple types - B, E, J, K, N, R, S and T - were re-characterised in 1993 to reflect the scale changes. (See: NIST Monograph 175 for details). The remaining types: C, D, G, L, M, P and U appear to have been informally re-characterised.Try the thermocouple calculator. It allows you the determine the temperature by knowing the measured voltage and the reference junction temperature.Thermocouple wire gradesThere are different grades of thermocouple wire. The principal divisions are between measurement grades and extension grades. The measurement grade has the highest purity and should be used where the temperature gradient is significant. The standard measurement grade (Class 2) is most commonly used. Special measurement grades (Class 1) are available with accuracy about twice the standard measurement grades.The extension thermocouple wire grades are designed for connecting the thermocouple to the measuring device. The extension wire may be of different metals to the measurement grade, but are chosen to have a matching response over a much reduced temperature range - typically -40°C to 120°C. The reason for using extension wire is reduced cost - they can be 20% to 30% of the cost of equivalent measurementgrades. Further cost savings are possible by using thinnergauge extension wire and a lower temperature rated insulation.Note: When temperatures within the extension wire's rating are being measured, it is OK to use the extension wire for the entire circuit. This is frequently done with T type extension wire, which is accurate over the -60 to 100°C range.Thermocouple wire gaugeAt high temperatures, thermocouple wire can under go irreversible changes in the form of modified crystal structure, selective migration of alloy components and chemical changes originating from the surface metal reacting to the surrounding environment. With some types, mechanical stress and cycling can also induce changes.Increasing the diameter of the wire where it is exposed to the high temperatures can reduce the impact of these effects.The following table can be used as a very approximate guide to wire gauge:At these higher temperatures, the thermocouple wire should be protected as much as possible from hostile gases. Reducing or oxidizing gases can corrode some thermocouple wire very quickly. Remember, the purity of the thermocouple wire is most important where the temperature gradients are greatest. It is with this part of the thermocouple wiring where the most care must be taken.Other sources of wire contamination include the mineral packing material and the protective metal sheath. Metallic vapour diffusion can be significant problem at high temperatures. Platinum wires should only be used inside a nonmetallic sheath, such as high-purity alumna.Neutron radiation (as in a nuclear reactor) can have significant permanent impact on the thermocouple calibration. This is due to the transformation of metals to different elements.High temperature measurement is very difficult in some situations. In preference, use non-contact methods. However this is not always possible, as the site of temperature measurement is not always visible to these types of sensors.Colour coding of thermocouple wireThe colour coding of thermocouple wire is something of a nightmare! There are at least seven different standards. There are some inconsistencies between standards, which seem to have been designed to confuse. For example the colour red in the USA standard is always used for the negative lead, while in German and Japanese standards it is always the positive lead. The British, French and International standards avoid the use of red entirely!Thermocouple mountingThere are four common ways in which thermocouples are mounted with in a stainless steel or Inconel sheath and electrically insulated with mineral oxides. Each of the methods has its advantages and disadvantages.Sealed and Isolated from Sheath: Good relatively trouble-free arrangement. The principal reason for not using this arrangement for all applications is its sluggish response time - the typical time constant is 75 secondsSealed and Grounded to Sheath: Can cause ground loops and other noise injection, but provides a reasonable time constant (40 seconds) and a sealed enclosure.Exposed Bead: Faster response time constant (typically 15 seconds), but lacks mechanical and chemical protection, and electrical isolation from material being measured. The porous insulating mineral oxides must be sealedExposed Fast Response: Fastest response time constant, typically 2 seconds but with fine gauge of junction wire the time constant can be 10-100 ms. In addition to problems of the exposed bead type, the protruding and light construction makes the thermocouple more prone to physical damage.Thermocouple compensation and linearizationAs mentioned above, it is possible to provide reference junction compensation in hardware or in software. The principal is the same in both cases: adding a correction voltage to the thermocouple output voltage, proportional to the reference junction temperature. To this end, the connection point of the thermocouple wires to the measuring device (i.e. where the thermocouple materials change to the copper of thecircuit electronics) must be monitored by a sensor. This area must be design to be isothermal, so that the sensor accurately tracks both reference junction temperatures.The hardware solution is simple but not always as easy to implement as one might expect.The circuit needs to be designed for a specific thermocouple type and hence lacks the flexibility of the software approach.The software compensation technique simplifies the hardware requirement, by eliminating the reference sensor amplifier and summing circuit (although a multiplexer may be required).The software algorithm to process the signals needs to be carefully written. A sample algorithm details the process.A good resource for thermocouple emf tables and coefficients is at the US Commerce Dept's NIST web site. It covers the B, E, J, K, N, R, S and T types.The thermocouple as a heat pumpThe thermocouple can function in reverse. If a current is passed through a thermocouple circuit, one junction will cool and the other warm. This is known as the Peltier Effect and is used in small cooling systems. The effect can be demonstrated by alternately passing a current through a thermocouple circuit and then quickly measuring the circuit's Seebeck voltage. This process has been used, with very fine thermocouple wire (0.025 mm with about a 10 mA current), to measure humidity by ensuring the cooled junction drops below the air's dew point. This causes condensation to form on the cooled junction. The junction is allowed to return to ambient, with the temperature curve showing an inflection at the dew point caused by the latent heat of vaporization.Measuring temperature differencesThermocouples are excellent for measuring temperatures differences, such as the wet bulb depression in measuring humidity. Sensitivity can be enhanced by constructing a thermopile - a number of thermocouple circuits in series.In the above example, the thermopile output is proportional to the temperaturedifference T1 - T2, with a sensitivity three times that of a single junction pair. In practice, thermopiles with two to hundreds of junctions are used in radiometers, heat flux sensors, flow sensors and humidity sensors. The thermocouple materials can be in wire form, but also printed or etched as foils and even electroplated.An excellent example of the thermopile is in the heat flux sensors manufactured by Hukseflux Thermal Sensors. Also see RdF Corp. and Exergen Corp.The thermocouple is unique in its ability to directly measure a temperature difference. Other sensor types require a pair of closely matched sensors to ensure tracking over the entire operational temperature range.The thermoelectric generatorWhile the Seebeck voltage is very small (in the order of 10-70μV/°C), if the circuit's electrical resistance is low (thick, short wires), then large currents are possible (e.g. many amperes). An efficiency trade-off of electrical resistance (as small as possible) and thermal resistance (as large as possible) between the junctions is the major issue. Generally, electrical and thermal resistances trend together with different materials. The output voltage can be increased by wiring as a thermopile.The thermoelectric generator has found its best-known application as the power source in some spacecraft. A radioactive material, such as plutonium, generates heat and cooling is provided by heat radiation into space. Such an atomic power source can reliably provide many tens of watts of power for years. The fact that atomic generators are highly radioactive prevents their wider application.译文:热电偶温度传感器热电偶的定义热电偶是最简单的传感器之一。

传感器外文翻译---传感器的基础知识

传感器外文翻译---传感器的基础知识

Basic knowledge of transducersA transducer is a device which converts the quantity being measured into an optical, mechanical, or-more commonly-electrical signal. The energy-conversion process that takes place is referred to as transduction.Transducers are classified according to the transduction principle involved and the form of the measured. Thus a resistance transducer for measuring displacement is classified as a resistance displacement transducer. Other classification examples are pressure bellows, force diaphragm, pressure flapper-nozzle, and so on.1、Transducer ElementsAlthough there are exception ,most transducers consist of a sensing element and a conversion or control element. For example, diaphragms,bellows,strain tubes and rings, bourdon tubes, and cantilevers are sensing elements which respond to changes in pressure or force and convert these physical quantities into a displacement. This displacement may then be used to change an electrical parameter such as voltage, resistance, capacitance, or inductance. Such combination of mechanical and electrical elements form electromechanical transducing devices or transducers. Similar combination can be made for other energy input such as thermal. Photo, magnetic and chemical,giving thermoelectric, photoelectric,electromaanetic, and electrochemical transducers respectively.2、Transducer SensitivityThe relationship between the measured and the transducer output signal is usually obtained by calibration tests and is referred to as the transducer sensitivity K1= output-signal increment / measured increment . In practice, the transducer sensitivity is usually known, and, by measuring the output signal, the input quantity is determined from input= output-signal increment / K1.3、Characteristics of an Ideal TransducerThe high transducer should exhibit the following characteristicsa) high fidelity-the transducer output waveform shape be a faithful reproduction of the measured; there should be minimum distortion.b) There should be minimum interference with the quantity being measured; the presence of the transducer should not alter the measured in any way.c) Size. The transducer must be capable of being placed exactly where it is needed.d) There should be a linear relationship between the measured and the transducer signal.e) The transducer should have minimum sensitivity to external effects, pressure transducers,for example,are often subjected to external effects such vibration and temperature.f) The natural frequency of the transducer should be well separated from the frequency and harmonics of the measurand.4、Electrical TransducersElectrical transducers exhibit many of the ideal characteristics. In addition they offer high sensitivity as well as promoting the possible of remote indication or mesdurement. Electrical transducers can be divided into two distinct groups:a) variable-control-parameter types,which include:i)resistanceii) capacitanceiii) inductanceiv) mutual-inductance typesThese transducers all rely on external excitation voltage for their operation.b) self-generating types,which includei) electromagneticii)thermoelectriciii)photoemissiveiv)piezo-electric typesThese all themselves produce an output voltage in response to the measurand input and their effects are reversible. For example, a piezo-electric transducer normally produces an output voltage in response to the deformation of a crystalline material; however, if an alternating voltage is applied across the material, the transducer exhibits the reversible effect by deforming or vibrating at the frequency of the alternating voltage.5、Resistance TransducersResistance transducers may be divided into two groups, as follows:i) Those which experience a large resistance change, measured by using potential-divider methods. Potentiometers are in this group.ii)Those which experience a small resistance change, measured by bridge-circuit methods. Examples of this group include strain gauges and resistance thermometers.5.1 PotentiometersA linear wire-wound potentiometer consists of a number of turns resistance wire wound around a non-conducting former, together with a wiping contact which travels over the barwires. The construction principles are shown in figure which indicate that the wiperdisplacement can be rotary, translational, or a combination of both to give a helical-type motion. The excitation voltage may be either a.c. or d.c. and the output voltage is proportional to the input motion, provided the measuring device has a resistance which is much greater than the potentiometer resistance.Such potentiometers suffer from the linked problem of resolution and electrical noise. Resolution is defined as the smallest detectable change in input and is dependent on thecross-sectional area of the windings and the area of the sliding contact. The output voltage is thus a serials of steps as the contact moves from one wire to next.Electrical noise may be generated by variation in contact resistance, by mechanical wear due to contact friction, and by contact vibration transmitted from the sensing element. In addition, the motion being measured may experience significant mechanical loading by the inertia and friction of the moving parts of the potentiometer. The wear on the contacting surface limits the life of a potentiometer to a finite number of full strokes or rotations usually referred to in the manufacture’s specification as the ‘number of cycles of life expectancy’, a typical value being 20*1000000 cycles.The output voltage V0 of the unload potentiometer circuit is determined as follows. Let resistance R1= xi/xt *Rt where xi = input displacement, xt= maximum possible displacement, Rt total resistance of the potentiometer. Then output voltage V0= V*R1/(R1+( Rt-R1))=V*R1/Rt=V*xi/xt*Rt/Rt=V*xi/xt. This shows that there is a straight-line relationship between output voltage and input displacement for the unloaded potentiometer.It would seen that high sensitivity could be achieved simply by increasing the excitation voltage V. however, the maximum value of V is determined by the maximum power dissipation P of the fine wires of the potentiometer winding and is given by V=(PRt)1/2 .5.2 Resistance Strain GaugesResistance strain gauges are transducers which exhibit a change in electrical resistance in response to mechanical strain. They may be of the bonded or unbonded variety .a) bonded strain gaugesUsing an adhesive, these gauges are bonded, or cemented, directly on to the surface of the body or structure which is being examined.Examples of bonded gauges arei) fine wire gauges cemented to paper backingii) photo-etched grids of conducting foil on an epoxy-resin backingiii)a single semiconductor filament mounted on an epoxy-resin backing with copper or nickel leads.Resistance gauges can be made up as single elements to measuring strain in one direction only,or a combination of elements such as rosettes will permit simultaneous measurements in more than one direction.b) unbonded strain gaugesA typical unbonded-strain-gauge arrangement shows fine resistance wires stretched around supports in such a way that the deflection of the cantilever spring system changes the tension in the wires and thus alters the resistance of wire. Such an arrangement may be found in commercially available force, load, or pressure transducers.5.3 Resistance Temperature TransducersThe materials for these can be divided into two main groups:a) metals such as platinum, copper, tungsten, and nickel which exhibit and increase in resistance as the temperature rises; they have a positive temperature coefficient of resistance.b) semiconductors, such as thermistors which use oxides of manganese, cobalt, chromium, or nickel. These exhibit large non-linear resistance changes with temperature variation and normally have a negative temperature coefficient of resistance.a) metal resistance temperature transducersThese depend, for many practical purpose and within a narrow temperature range, upon the relationship R1=R0*[1+a*(b1-b2)] where a coefficient of resistance in ℃-1,and R0 resistance in ohms at the reference temperature b0=0℃ at the reference temperature range ℃.The international practical temperature scale is based on the platinum resistance thermometer, which covers the temperature range -259.35℃ to 630.5℃.b) thermistor resistance temperature transducersThermistors are temperature-sensitive resistors which exhibit large non-liner resistance changes with temperature variation. In general, they have a negative temperature coefficient. For small temperature increments the variation in resistance is reasonably linear; but, if large temperature changes are experienced, special linearizing techniques are used in the measuring circuits to produce a linear relationship of resistance against temperature.Thermistors are normally made in the form of semiconductor discs enclosed in glass vitreous enamel. Since they can be made as small as 1mm,quite rapid response times are possible.5.4 Photoconductive CellsThe photoconductive cell , uses a light-sensitive semiconductor material. The resistance between the metal electrodes decrease as the intensity of the light striking the semiconductor increases. Common semiconductor materials used for photo-conductive cells are cadmium sulphide, lead sulphide, and copper-doped germanium.The useful range of frequencies is determined by material used. Cadmium sulphide is mainly suitable for visible light, whereas lead sulphide has its peak response in the infra-red regionand is, therefore , most suitable for flame-failure detection and temperature measurement. 5.5 Photoemissive CellsWhen light strikes the cathode of the photoemissive cell are given sufficient energy to arrive the cathode. The positive anode attracts these electrons, producing a current which flows through resistor R and resulting in an output voltage V.Photoelectrically generated voltage V=Ip.RlWhere Ip=photoelectric current(A),and photoelectric current Ip=Kt.BWhere Kt=sensitivity (A/im),and B=illumination input (lumen)Although the output voltage does give a good indication of the magnitude of illumination, the cells are more often used for counting or control purpose, where the light striking the cathode can be interrupted.6、Capacitive TransducersThe capacitance can thus made to vary by changing either the relative permittivity, the effective area, or the distance separating the plates. The characteristic curves indicate that variations of area and relative permittivity give a linear relationship only over a small range of spacings. Thus the sensitivity is high for small values of d. Unlike the potentionmeter, the variable-distance capacitive transducer has an infinite resolution making it most suitable for measuring small increments of displacement or quantities which may be changed to produce a displacement.7、Inductive TransducersThe inductance can thus be made to vary by changing the reluctance of the inductive circuit. Measuring techniques used with capacitive and inductive transducers:a)A.C. excited bridges using differential capacitors inductors.b)A.C. potentiometer circuits for dynamic measurements.c) D.C. circuits to give a voltage proportional to velocity for a capacitor.d) Frequency-modulation methods, where the change of C or L varies the frequency of an oscillation circuit.Important features of capacitive and inductive transducers are as follows:i)resolution infiniteii) accuracy+- 0.1% of full scale is quotediii)displacement ranges 25*10-6 m to 10-3miv) rise time less than 50us possibleTypical measurands are displacement, pressure, vibration, sound, and liquid level.8、Linear Variable-differential Ttransformer9、Piezo-electric Transducers10、Electromagnetic Transducers11、Thermoelectric Transducers12、Photoelectric Cells13、Mechanical Transducers and Sensing Elements传感器的基础知识传感器是一种把被测量转换为光的、机械的或者更平常的电信号的装置。

红外传感器中英文对照外文翻译文献

红外传感器中英文对照外文翻译文献

中英文对照翻译外文资料Moving Object Counting with an Infrared Sensor NetworkAbstractWireless Sensor Network (WSN) has become a hot research topic recently. Great benefit can be gained through the deployment of the WSN over a wide range ofapplications, covering the domains of commercial, military as well as residential. In this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. Such a system can be deployed in traffic control, resource management, and human flow control. Our design is based on our self-made cost-effective Infrared Sensing Module board which co-operates with a WSN. The design of our system includes Infrared Sensing Module design, sensor clustering, node communication, system architecture and deployment. We conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our Moving Object Counting system.Keywords:Infrared radiation,Wireless Sensor Node1.1 Introduction to InfraredInfrared radiation is a part of the electromagnetic radiation with a wavelength lying between visible light and radio waves. Infrared have be widely used nowadaysincluding data communications, night vision, object tracking and so on. People commonly use infrared in data communication, since it is easily generated and only suffers little from electromagnetic interference. Take the TV remote control as an example, which can be found in everyone's home. The infrared remote control systems use infrared light-emitting diodes (LEDs) to send out an IR (infrared) signal when the button is pushed. A different pattern of pulses indicates the corresponding button being pushed. To allow the control of multiple appliances such as a TV, VCR, and cable box, without interference, systems generally have a preamble and an address to synchronize the receiver and identify the source and location of the infrared signal. To encode the data, systems generally vary the width of the pulses (pulse-width modulation) or the width of the spaces between the pulses (pulse space modulation). Another popular system, bi-phase encoding, uses signal transitions to convey information. Each pulse is actually a burst of IR at the carrier frequency.A 'high' means a burst of IR energy at the carrier frequency and a 'low' represents an absence of IR energy. There is no encoding standard.However, while a great many home entertainment devices use their own proprietary encoding schemes, some quasi-standards do exist. These include RC-5, RC-6, and REC-80. In addition, many manufacturers, such as NEC, have also established their own standards.Wireless Sensor Network (WSN) has become a hot research topic recently. Great benefit can be gained through the deployment of the WSN over a wide range ofapplications, covering the domains of commercial, military as well as residential. In this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. Such a system can be deployed in traffic control, resource management, and human flow control. Our design is based on our self-made cost-effective Infrared Sensing Module board which co-operates with a WSN. The design of our system includes Infrared Sensing Module design, sensor clustering, node communication, system architecture and deployment. We conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our Moving Object Counting system.1.2 Wireless sensor networkWireless sensor network (WSN) is a wireless network which consists of a vast number of autonomous sensor nodes using sensors to monitor physical or environmental conditions, such as temperature,acoustics, vibration, pressure, motion or pollutants, at different locations. Each node in a sensor network is typically equipped with a wireless communications device, a small microcontroller, one or more sensors, and an energy source, usually a battery. The size of a single sensor node can be as large as a shoebox and can be as small as the size of a grain of dust, depending on different applications. The cost of sensor nodes is similarly variable, ranging from hundreds of dollars to a few cents, depending on the size of the sensor network and the complexity requirement of the individual sensor nodes. The size and cost are constrained by sensor nodes, therefore, have result in corresponding limitations on available inputs such as energy, memory, computational speed and bandwidth. The development of wireless sensor networks (WSN) was originally motivated by military applications such as battlefield surveillance. Due to the advancement in micro-electronic mechanical system technology (MEMS), embedded microprocessors, and wireless networking, the WSN can be benefited in many civilian application areas, including habitat monitoring, healthcare applications, and home automation.1.3 Types of Wireless Sensor NetworksWireless sensor network nodes are typically less complex than general-purpose operating systems both because of the special requirements of sensor network applications and the resource constraintsin sensor network hardware platforms. The operating system does not need to include support for user interfaces. Furthermore, the resource constraints in terms of memory and memory mapping hardware support make mechanisms such as virtual memory either unnecessary or impossible to implement. TinyOS [TinyOS] is possibly the first operating system specifically designed for wireless sensor networks. Unlike most other operating systems, TinyOS is based on an event-driven programming model instead of multithreading. TinyOS programs are composed into event handlers and tasks with run to completion-semantics. When an external event occurs, such as an incoming data packet or a sensor reading, TinyOS calls the appropriate event handler to handle the event. The TinyOS system and programs are both written in a special programming language called nesC [nesC] which is an extension to the C programming language. NesC is designed to detect race conditions between tasks and event handlers. There are also operating systems that allow programming in C. Examples of such operating systems include Contiki [Contiki], and MANTIS. Contiki is designed to support loading modules over the network and supports run-time loading of standard ELF files. The Contiki kernel is event-driven, like TinyOS, but the system supports multithreading on a per-application basis. Unlike the event-driven Contiki kernel, the MANTIS kernel is based on preemptive multithreading. With preemptive multithreading, applications do not needto explicitly yield the microprocessor to other processes.1.4 Introduction to Wireless Sensor NodeA sensor node, also known as a mote, is a node in a wireless sensor network that is capable of performing processing, gathering sensory information and communicating with other connected nodes in the network. Sensor node should be in small size, consuming extremely low energy, autonomous and operate unattended, and adaptive to the environment. As wireless sensor nodes are micro-electronic sensor device, they can only be equipped with a limited power source. The main components of a sensor node include sensors, microcontroller, transceiver, and power source. Sensors are hardware devices that can produce measurable response to a change in a physical condition such as light density and sound density. The continuous analog signal collected by the sensors is digitized by Analog-to-Digital converter. The digitized signal is then passed to controllers for further processing. Most of the theoretical work on WSNs considers Passive and Omni directional sensors. Passive and Omni directional sensors sense the data without actually manipulating the environment with active probing, while no notion of “direction” involved in these measurements. Commonly people deploy sensor for detecting heat (e.g. thermal sensor), light (e.g. infrared sensor), ultra sound (e.g. ultrasonic sensor), or electromagnetism (e.g. magnetic sensor). In practice, a sensor node can equip with more than one sensor.Microcontroller performs tasks, processes data and controls the operations of other components in the sensor node. The sensor node is responsible for the signal processing upon the detection of the physical events as needed or on demand. It handles the interruption from the transceiver. In addition, it deals with the internal behavior, such as application-specific computation.The function of both transmitter and receiver are combined into a single device know as transceivers that are used in sensor nodes. Transceivers allow a sensor node to exchange information between the neighboring sensors and the sink node (a central receiver). The operational states of a transceiver are Transmit, Receive, Idle and Sleep. Power is stored either in the batteries or the capacitors. Batteries are the main source of power supply for the sensor nodes. Two types of batteries used are chargeable and non-rechargeable. They are also classified according to electrochemical material used for electrode such as NiCd(nickel-cadmium), NiZn(nickel-zinc), Nimh(nickel metal hydride), and Lithium-Ion. Current sensors are developed which are able to renew their energy from solar to vibration energy. Two major power saving policies used areDynamic Power Management (DPM) and Dynamic V oltage Scaling (DVS). DPM takes care of shutting down parts of sensor node which are not currently used or active. DVS scheme varies the power levelsdepending on the non-deterministic workload. By varying the voltage along with the frequency, it is possible to obtain quadratic reduction in power consumption.1.5 ChallengesThe major challenges in the design and implementation of the wireless sensor network are mainly the energy limitation, hardware limitation and the area of coverage. Energy is the scarcest resource of WSN nodes, and it determines the lifetime of WSNs. WSNs are meant to be deployed in large numbers in various environments, including remote and hostile regions, with ad-hoc communications as key. For this reason, algorithms and protocols need to be lifetime maximization, robustness and fault tolerance and self-configuration. The challenge in hardware is to produce low cost and tiny sensor nodes. With respect to these objectives, current sensor nodes usually have limited computational capability and memory space. Consequently, the application software and algorithms in WSN should be well-optimized and condensed. In order to maximize the coverage area with a high stability and robustness of each signal node, multi-hop communication with low power consumption is preferred. Furthermore, to deal with the large network size, the designed protocol for a large scale WSN must be distributed.1.6 Research IssuesResearchers are interested in various areas of wireless sensornetwork, which include the design, implementation, and operation. These include hardware, software and middleware, which means primitives between the software and the hardware. As the WSNs are generally deployed in the resources-constrained environments with battery operated node, the researchers are mainly focus on the issues of energy optimization, coverage areas improvement, errors reduction, sensor network application, data security, sensor node mobility, and data packet routing algorithm among the sensors. In literature, a large group of researchers devoted a great amount of effort in the WSN. They focused in various areas, including physical property, sensor training, security through intelligent node cooperation, medium access, sensor coverage with random and deterministic placement, object locating and tracking, sensor location determination, addressing, energy efficient broadcasting and active scheduling, energy conserved routing, connectivity, data dissemination and gathering, sensor centric quality of routing, topology control and maintenance, etc.中文译文移动目标点数与红外传感器网络摘要无线传感器网络(WSN)已成为最近的一个研究热点。

传感器外文翻译

传感器外文翻译

毕业设计(论文)外文文献翻译院系:光电与通信工程年级专业:12电子信息工程姓名:刘燊学号:1106012133附件:Advances in Sensor Technology Development指导老师评语:指导教师签名:年月日——摘自夏伟强,樊尚春传感器技术的的新发展仪器仪表学报传感器技术的新进展传感器技术是新技术革命和信息社会的重要技术基础,是一门多学科交叉的科学技术,被公认为现代信息技术的源头。

近些年,传感器技术发展很快,取得了许多新进展,尤其在气体传感器、生物传感器、视觉传感器等方面取得了很多进展。

美国麻省理工学院华人科学家张曙光领导的研究小组借助一种特殊溶液,成功地找到了大规模制造嗅觉感受器的办法;同样是麻省理工学院的研究人员利用气相色谱-质谱技术感受识别气体分子,研制出一种能对微量有毒气体做出强烈反应的微型传感器;俄罗斯科学家以从一种普通蘑菇中提取的混合物为原料,与压电石英晶振构成谐振式传感器,能够探测空气中含量极低的酚成分;日本科学家研制出能快速识别流感病毒纳米传感器,有望以纳米技术为快速识别流感病毒、乙型肝炎病毒、疯牛病病原体和残留农药等物质提供新手段;西班牙巴塞罗那自治大学研制出新型缩微DNA分析传感器,这种传感器能将分析 DNA链的时间缩短到几分钟或几小时,智能仪器与传感器技术、空间生物智能传感技术。

可以在亲子鉴定到检测遗传修饰食物的一系列化验中应用,此外还能确定新药的遗传毒性;美国国家标准与技术研究院研发出一种超灵敏微型核磁共振(NMR)传感器,该微型传感器与微流体通道并列置于一个硅芯片之上,这项技术将核磁共振的探测灵敏度提升到一个新的台阶,将在化学分析中具有广泛的应用前景。

我国传感器技术虽然与国外相比还有很大差距,但近两年也取得了一些进展和突破,诞生了一些新产品,有些在国家重大型号工程中获得应用。

如资源环境技术领域中的环境监测及环境风险评价技术、大气复合污染关键气态污染物的快速在线监测技术和大气细粒子和超细粒子的快速在线监测技术,海洋技术领域中的海洋水质污染综合参数在线监测技术和海洋金属污染物现场和在线监测技术等。

电容式传感器的外文文献翻译、中英文翻译、外文翻译

电容式传感器的外文文献翻译、中英文翻译、外文翻译

参考资料原文:Capacitive sensors and the main features of the basic concepts: The measured volume of the machinery, such as displacement, pressure change is converted to the sensor capacitance. It is the sensitive part of the capacitor with variable parameters. Its most common form is composed of two parallel electrodes, a very inter-air as the medium of the capacitor, if the neglect edge effects, the capacitance for the capacitor plate ε A / δ, where εis a very inter-medium dielectric constant, A two electrode effective area covered by each other, δ is the distance between two electrodes. δ, A, εone of the three parameters will lead to the change in capacitance changes can be used for measurement. Therefore capacitive sensors can be divided into polar distance change type, change type size, media type three types of changes.Most from the changes in small type generally used to measure the linear displacement, or as a result of force, pressure, vibration caused by changes in polar distance (see capacitive pressure sensors). Change type size generally used to measure the angular displacement or linear displacement larger. Changes in media type commonly used in level measurement and a variety of media, temperature, density, humidity measurement. The advantage of the sensor capacitor structure is simple, inexpensive, high sensitivity,过载能力strong, good dynamic response and high temperature, radiation, vibration and other adverse conditions of strong adaptability and strong. The disadvantage is that there are non-linear output, parasitic capacitance and the distributed capacitance on the sensitivity and accuracy the impact of larger and more complex circuits, such as connectivity. Since the late 70s, with the development of integrated circuit technology, a packaging and micro-measuring instrument with capacitive sensors.This new type of distributed capacitance sensors can greatly reduce the impact to overcome the inherent drawbacks. Capacitive sensor is a very wide use, a great potential for development of the sensor.Capacitive sensor working principle:Capacitive sensor surface of the induction of two coaxial metal electrode composition, much like "open" capacitor electrode, the two electrodes form a capacitor, in series with the RC oscillation circuit. Power when connected, RC oscillator is notoscillating, when a goal of moving around electrical capacitor, the capacitor capacity increased, the oscillator to start oscillation. Circuit after the passage of the deal, will be two kinds of vibration and vibration signals into switching signals, which played a detection purpose of the existence of any objects. The sensor can detect metal objects, but also to detect non-metallic objects, metal objects can move away from the largest, non-metallic objects on the decision to move away from the dielectric constant material, the greater the dielectric constant materials, the availability of action the greater distance.Application of capacitive sensors:Capacitive sensor can be used to measure linear displacement, angular displacement, vibration amplitude, especially suitable for measuring high-frequency vibration amplitude, precision rotary axis accuracy, acceleration and other mechanical parameters. Pole-changing type of application from a smaller displacement in the measurement range to several hundred microns in 0.01m, precision can reach 0.01m, a resolution of up to 0.001m. Change type size larger displacement can be measured, for the zero-range a few millimeters to a few hundred mm, 0.5 percent better than the linear resolution of 0.01 ~ 0.001m. Capacitive angular displacement sensor point of view and the dynamic range to a few degrees, a resolution of about 0.1 "up to the stability of the zero angle-second, widely used in precision angle measurement, such as for high-precision gyroscopes and accelerometers tilting . capacitive measurement sensor can measure the peak amplitude for the 0 ~ 50m, a frequency of 10 ~ 2kHz, sensitivity is higher than 0.01m, non-linear error of less than 0.05m.Capacitive sensor can also be used to measure pressure, differential pressure, level, surface, composition content (such as oil, the water content of food), non-metallic coating materials, such as film thickness, dielectric measurements of humidity, density, thickness, etc., in the automatic detection and control systems are also often used as a location signal generator. Capacitive differential pressure sensor measuring range up to 50MPa, an accuracy of ± 0.25% ~ ± 0.5%. Capacitive sensor for measuring range of the thickness of a few hundred microns, resolution of up to 0.01m. Capacitive Proximity Switches can not only detect metal, but also can detect plastic, wood,paper, and other dielectric liquids, but can not achieve the ultra-small, the movement distance of about 10 ~ 20mm. Electrostatic capacitive level switch is widely used in detection is stored in the tank, hopper, such as the location of containers in a variety of objects of a mature product. When the capacitive sensor measuring metal surface conditions, from the size, vibration amplitude is often used very variable from unilateral type, when the measured object is a capacitor electrode, and the other electrode in the sensor inside. This type of sensor is a non-contact measurement, dynamic range is relatively small, about a few millimeters is about the precision of more than 0.1m, a resolution of 0.01 ~ 0.001m.译文:电容式传感器的基本概念及主要特点:把被测的机械量,如位移、压力等转换为电容量变化的传感器。

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附录3:外文翻译资料Development of Sensor New TechnologySensor is one kind component which can tansform the physical quantity, ch emistry quantity and the biomass into electrical signal. The output signal has the different forms like the voltage, the electric current, the frequency, the pulse and so on, which can satisfy the signal transmission, processing, recording, demon stration and control demands. So it is the automatic detection system and in the a utomatic control industry. If automatic Technology is used wider, then sensor is more important. In information age, the information industry includs informatio n gathering, transmission, process three parts, namely sensor technology, com munication, computer technology. Because of ultra large scale integrated circuit’s rapid development after having been developed ,Modern computer technology and communication, not only requests sensor precision, reliability, speed of res ponse and gain information content request more and more high, but also reques ts its cost to be inexpensive. The obvious traditional sensor is eliminated gradual ly because of the function, the characteristic, the volume, the cost and so on. As world develop many countries are speeding up to the sensor new technology’s r esearch and the development, and all has obtained the enormous breakthrough. Now the sensor new technology development, mainly has following several aspe cts:Firstly, discovering and using.Using the physical phenomenon, the chemical reaction, the biological effe ct as the sensor principle therefore the researches which discovered the new phe nomenon and the new effect are the sensor technological improving ways .it is i mportantstudies to develope new sensor’s the foundation. Japanese Sharp Corpo ration uses the superconductivity technology to develop successfully the high te mperature superconductivity magnetic sensor and get the sensor technology significant breakthrough. Its sensitivity is so high and only inferior in the supercond uctivity quantum interference component. Its manufacture craft is far simpler tha n the superconductivity quantum interference component. May use in magnetis m image formation technology.So it has the widespread promoted value.Using the immune body and the antigen meets one another compound whe n the electrode surface.It can cause the electrode potential change and use this p henomenon to be possible to generate the immunity sensor. The immunity senso r makes with this kind of immune body may to some organism in whether has th is kind of anti- original work inspection. Like may inspect somebody with the he patitis virus immune body whether contracts the hepatitis, plays to is fast, the ac curate role. The US UC sixth branch has developped this kind of sensor. Secondly, using the new material.The sensor material is the important foundation for sensor technology, bec ause the materials science is progressive and the people may make each kind of new sensor. For example making the temperature sensor with the high polymer t hin film; The optical fiber can make the pressure, the current capacity, the tempe rature, the displacement and so on the many kinds of sensors; Making the pressu re transmitter with the ceramics. The high polymer can become the proportion a dsorption and the release hydrone along with the environment relative humidity size. The high polymer electricity lies between the constant to be small, the hydr one can enhance the polymer the coefficient of dielectrical loss. Making the cap acitor the high polymer dielectric medium, determines the electric capacity capa city the change, then obtains the relative humidity. Making the plasma using this principle to gather the legitimate polystyrene film temperature sensor below, it has the characteristic:Measured the wet scope is wide;The temperature range is wide, may reach -400 ℃ ~ +1,500 ℃;The speed of response is quick, is smaller than 1S;The size is small, may use in the small space measuring wet;The temperature coefficient is small.The ceramic electric capacity type pressure transmitter is one kind does not have the intermediary fluid the dry type pressure transmitter. Uses the advanced ceramic technology, the heavy film electronic technology, its technical performa nce is stable, the year drifting quantity is smaller than 0.1%F.S, warm floats is s maller than ±0.15%/10K, anti- overloads strongly, may reach the measuring ran ge several hundred times. The survey scope may from 0 to 60mpa. German E+H Corporation and the American Kavlio Corporation product is at the leading posi tion.The optical fiber application is send the material significant breakthrough, i ts uses in most early the optical communication techniques. In the optical comm unication use discovered works as environmental condition change and so on the temperature, pressure, electric field, magnetic field, causes the fiber optic trans mission light wave intensity, the phase, the frequency, change and so on the pola rization condition, the survey light wave quantity change, may know causes thes e light wave physical quantity the and so on quantitative change temperature, pr essure, electric field, magnetic field size, uses these principles to be possible to d evelop the optical fiber sensor. The optical fiber sensor and the traditional sensor compare has many characteristics: Sensitivity high, the structure simple, the vol ume small, anti-corrosive, the electric insulation good, the path of rays may be c urving, be advantageous for the realization telemetering and so on. Optical fiber sensor Japan is in the advanced level. Like Idec Izumi Corporation and Sunx Co rporation. The optical fiber send receiver and the integrated path of rays technol ogy unify, accelerates the optical fiber sensor technology development. Will inte grate the path of rays component to replace the original optics part and the passi ve light component, enable the optical fiber sensor to have the high band width, the low signal processing voltage, the reliability high, the cost will be low.Third, micro machine-finishing technologyIn semiconductor technology processing method oxygenation, the photoetc hing, the proliferation, the deposition, the plane electron craft, various guides corrosion and steams plates, the sputtering thin film and so on, these have all intro duced to the sensor manufacture. Thus has produced each kind of new s ensor, like makes the silicon micro sensor using the semiconductor technol ogy, makes the fast response using the thin film craft the gas to be sensitive, the wet sensitive sensor, the use sputtering thin film craft system pressure transmitte r and so on.The Japanese horizontal river company uses various guides corrosion technolo gy to carry on the high accuracy three dimensional processing, the system helps the silicon resonance type pressure transmitter. The core partially presses two re sonant Liang by the feeling which above the silicon diaphragm and the silicon di aphragm manufactures to form, two resonant Liang's frequency difference corre spondence different pressure, measures the pressure with the frequency differenc e method, may eliminate the error which factor and so on ambient temperature b rings. When ambient temperature change, two resonant Liang frequency and the amplitude variation are same, after two frequency differences, its same change q uantity can counterbalance mutually. Its survey most high accuracy may reach 0. 01%FS.American Silicon Microstructure Inc.(SMI) the company develops a series of low ends, linear in 0.1% to 0.In 65% scope silicon micro pressure transmitter, the lowest full measuring range is 0.15psi (1KPa), it makes take the silicon as th e material, has the unique three dimensional structure, the light slight machine-fi nishing, makes the wheatstone bridge many times with the etching on the silicon diaphragm, when above silicon chip stress, it has the distortion, the resistance p roduces presses the anti- effect but to lose the bridge balance, the output and the pressure becomes the proportion the electrical signalSuch silicon micro sensor is the front technology which now the sensor dev elops,Its essential feature is the sensitive unit volume is a micron magnitude,Is t he traditional sensor several dozens, several 1%. In aspect and so on industry co ntrol, aerospace domain, biomedicine has the vital role, like on the airplane the u se may reduce the airplane weight, reduces the energy. Another characteristic iscan be sensitive is small surveyed, may make the blood pressure pressure transm itter.The Chinese aviation main corporation Beijing observation and control tec hnical research institute, the development CYJ series splashes thanks the membr ane pressure transmitter is uses the ion sputtering craft to process the metal strai n gauge, it has overcome the nonmetallic strain gauge easily the temperature infl uence insufficiency, has the high stability, is suitable in each kind of situation, is measured the medium scope widely, but also overcame the tradition lowly to glu e the precision which the type brought, sluggish big, shortcoming and so on slo w change, had the precision high, the reliability is high, the volume small charac teristic, widely used in domain and so on aviation, petroleum, chemical industry, medical service.Fourth, integrates the sensorIntegrates the sensor the superiority is the traditional sensor is unable to achieve, it is a simple sensor not merely, it in at the same time the auxiliary circuit part a nd send the part will integrate on together the chip, will cause it to have the calib ration, to compensate, from the diagnosis and the network correspondence functi on, it might reduce the cost, the gain in yield, this kind of blood pressure sensor which American LUCAS, NOV ASENSOR Corporation will develop, each week will be able to produce 10,000.Fifth, intellectualized sensorThe intellectualized sensor is one kind of belt microprocessor sensor, is ach ievement which the microcomputer and the sensor unifies, it has at the same tim e the examination, the judgment and the information processing function, compa res with the traditional sensor has very many characteristics:Has the judgment a nd the information processing function, can carry on the revision, the error to the observed value compensates, thus enhancement measuring accuracy; May reali ze the multi-sensor multi parameters survey; Has from the diagnosis and from th e calibration function, enhances the reliability; The survey data may deposit and withdraw, easy to operate; Has the data communication interface dci, can and the microcomputer direct communication.The sensor, the signal adjustment electric circuit, the monolithic integrated circuit integration forms ultra large-scale integrated on a chip the senior intellige nce sensor. American HONY WELL Corporation ST-3000 intelligence sensor, th e chip size only then has 3×4×2mm3, uses the semiconductor craft, makes CPU, EPROM, the static pressure, the differential pressure, the temperature on the ide ntical chip and so on three kind of sensitive units.The intellectualized sensor research and the development, US is at the leading p osition. American Space Agency when development spaceship called this kind o f sensor for the clever sensor (Smart Sensor), on the spaceship this kind of senso r is extremely important. Our country in this aspect research and development al so very backward, mainly is because our country semiconductor integrated circu it technological level is limited.The sensor’s development is changing day after day since specially the 80's hum anities have entered into the high industrialization the information age, sensor te chnology to renewal, higher technological development. US, Japan and so on de veloped country sensor technological development quickest, our country becaus e the foundation is weak, the sensor technology compares with these developed countries has the big disparity. Therefore, we should enlarge to the sensor engine ering research, the development investment, causes our country sensor technolo gy and the foreign disparity reduces, promotes our country instrument measurin g appliance industry and from the technical development.传感器新技术的发展传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。

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