测控技术与仪器类中英文翻译、外文翻译
存储测试系统的设计理论——测控技术与仪器类中英文翻译、外文翻译
Design theory of stored testing and measuring system and its realization in dynamic data measurement of missileBeijing Institute of TechnologyStored testing and measuring is a kind of dynamic test technology wherein micro data recording gauge is embedded in the object to be measured in the condition that there is no or allowable effect on it. The information is collected and memorized at the spot in real time. The recording device is recollected and computer is used to process the measured information. The key to realize dynamic stored testing and measuring lies in developing of stored testing and measuring system (STMS) that can work normally in the testing environment and have either no effect on the object to be measured or the effect is in the allowable range.The definition, character, application field and basic elements are studied systematically. The overall review of research and development situation in home and oversea is given. During Ph.D candidate studying period, the author has presided over the development of data-recording devices used on 60 channels dynamic data testing and measuring (TM) during atmosphere-reentering of intercontinental ballistic missile (ICBM) warhead, intelligent missile blockbox used on dynamic data-recording of certain heavy anti-tank missile flight, anti-warship missile slip track flight fuse data testing and measuring system, cannon shoot missile ball cartridge flight data-recording device, STMS of inner overloading curve of penetrative pill and ball chamber. Based on these experiences the author analyses thoroughly the inner rules of testing and measuring technology and summarize the design concept and design rules in a philosophical view. The design principles that can conduct theengineering practice of STM are established, which make the design of STMS optimized in a logical and rational way.The STMS researched in the paper mainly used in the special environment with the following attributes: (1) transient single process;(2)multi-parameter interrelation, strict time-relation and the need of precise measuring simultaneously; (3) analogue and digital information, high range transient signal and micro range slow-change signal exist simultaneously (the range difference greater than four orders and both the amplitude-testing and the process-recording is needed); (4) bad testing and measuring environment, for example, high temperature up to 3000℃, high press up to 1000Mpa, 100,000g strong impact vibration , high rotate speed and strong magnetic disturbance; (5)the measured system is high-technology product with expensive test (up to tens of millions RMB for one experiment); (6) small test space (no disturbance to the tested system is required and effect be smallest); (7) difficult to recovery; and so on.After systematically studying many of the STMS examples, the design theory and ten microscopical design principles of STMS are presented. They include realizability of working principle, recollectability of testing and measuring data, matching and/or harmonizing, compatibility, environment-adaptability, reusing and calibrationability, flexible design, modularization design, optimizing and trade-off of technology schemes. The conception of state design of STMS is firstly presented. The basic conceptions (for example, STMS state, state variable, state space, state net, state assemble and state chain) are defined, followed by studying of state assemble, establishing of state chain and/or state net design principles and methods. Further, their application scope and typical applications are illustrated. The time power factor theory andthe mathematics description of system state and its transformation are presented.Considering STMS as an information transmission system, the information transmission model of it is established. The testing and measuring information flow, equivalent information transmission model and noise model are analyzed. From the information transmission view, the similarity between STMS and Shannon communication system is compared to establish the theory basis for studying TM channel by application information theory.Quantify algorithmic defining information of measured signal that make use of entropy and entropy power has been presented, including TM channel capacity principle, the maxim interinformation principle and information rate distortion principle. Channel capacity of continuous analogue signal TM and anti-disturbance capacity limitation. The relation equation between STM channel transmission information and signal energy as well as TM channel anti-disturbance capacity limitation equation is established. The optimization analogue signal TM channel is presented, based on analysis of channel frequency character and information entropy, the maxim SNR condition of TM channel and the condition wherein both the minim TM channel output waveform and the maxim SNR condition are obtained. In the design of TM channel information the conception of distortion and rate distortion is introduced, moreover, the calculation equation of TM channel information rate distortion function is established.STMS digital signal TM channels are composed of one or more duality signal channel. In the paper, the digital test channels are synthesized as a combinaiton of “Z” channel and the channel of symmetric disturbed information. The basic channel and channel capacity as well as caculaiton of channel overlap probability are researched. Moreover, the informationchannels capacity and the best channels layout of test instruction channels and test data channels are discussed.Sampling and quantizing are the most important technology in STMS, which is related to information obtaining quality and STM precision. In common sampling TM system, the sampling frequency setup is inclined to be high (especially while the measured object is not known clearly) in order to obtain enough data. Thus, there is much information redundancy. Real time information compression technology must be developed so that more information that is useful can be recorded in the limited memory (reversely, the STMS cost can be reduced since the needed memory capacity is compressed).According to the attribute of the measured signal, the TM requirement, working environment and so on, the basic problems of STM sampling design are researched. Four STM sampling strategy (uniformity sampling, automatic subsection uniformity sampling, programmable self-adaptive subsection uniformity sampling and self-adaptive sampling) are presented. The algorithm of zero order and one order predictable self-adaptive sampling is introduced in detail. The source of sampling error and the method to avoid it are analyzed and researched.Two kinds of sampling signal quantizers (uniformity and ununiformity) are presented. The information rate distortion function of the uniformity quantizer and the SNR algorithm are established. The signal capacity and multi-channel information TM principle is researched. The alternative principle of ADC multi-channel transducer is presented.Information can be stored in magnetic memory dielectric (MMD) or semiconductor CMOS memory. The latter is commonly used in STMS due to complex control, large volume and low anti over-loading ability of MMD.Information memory subsystem in STMS is studied and designed. Moreover, information memory effective principles are presented, including: (1) Designing memory controller in term of sampling sequence and recording mode. (2) For address generator composed of serial counter, the propulsion of address is done by the rising edge of WR signal. (3) Reducing memory sub system transmission time as possible as one can or making the CMOS memory operation during transmission invalid.Based on study of the information compression principle, two information compressive storing algorithms are presented. One is the algorithm of finite span error limitation used in real time dynamic data collecting. The computer simulation shows that the algorithm is very effective in real-time data compression and storage (data compressive ratio up to 13.6 and memory space save up to 92%). The other is data model compressive algorithm based on dynamic data modeling. Error tolerence technology and redundancy design of STMS are also researched.The double-circle-recording principal and method for improving reliability in measuring transient signals is illustrated. The essential technologies of STMS, including three-micro technology (microvolume, micropower, micronoise), anti high over-loading technology and interface technology etc. are discussed in detail.DF-5A missile is a kind of middle/long distance strategy nuclear missile. It is a necessary task in missile system research to test and measure missile ball cartridge flight dynamic data. In the past, dynamic data of missile system are obtained by the wireless remote test system and magnetic tape recording device. Since plasma intermit section is “black area” of wireless system, missile dynamic data can’t be recorded by wireless remote test. Memory resending wireless remote test can be used to obtain “black area” data, however, only limited dynamic data beforethe missile head contact the ground can be obtained since missile head approach the ground quickly after leaving the “black area”. The other method is micro magnetic tape device on board, but the device operation is complex and the reliability is low.Under the instruction of principle mentioned above, dynamic STMS for a new strategy missile full ballistic trajectory is developed. Without the complex operation of traditional magnetic tape recording devices before blasting-off, the STMS can both inspect 60 channels dynamic data from distance far to 300m and complete inspection and store of missile head system data without dismounting the missile. The device can precisely do the testing and measuring task while the missile head reenter atmosphere plasma intermit section. It’s reliability is higher than magnetic recording devices and it is simpler than wireless remote test system. As substitution of onboard magnetic devices, the STMS is one of the most important measure means of missile head.In the paper the design theory, basic element, working principle, essential technology and reliability experiment of the missile data-recording device are illustrated in detail.The onboard flight test of missile data-recording device was carried out in July, 1995. During atmosphere-reentering of missile head in the experiment the wireless system was invalid, the magnetic-recording devices was broken down, only the STMS devices obtained 60 channel dynamic data during DF-5A reentering atmosphere and the result is highly-praised by the customer.存储测试系统的设计理论存储测试是指在对被测对象无影响或影响在允许范围的条件下, 在被测体内置入微型数据采集与存储测试仪, 现场实时完成信息的快速采集与记忆, 事后回收记录仪, 由计算机处理和再现测试信息的一种动态测试技术。
测控技术与仪器专业英语阅读翻译
测控技术与仪器专业英语阅读翻译篇一：测控技术与仪器专业英语翻译5. InheritanceIn Figure , the classes SalesOrderCheclcPmt and SalesOrderCreditPmt are called subclasses of SalesOrder. The class SalesOrder is called the super class of SalesOrderCheckPmt and SalesOrderCreditPmt. The relationship between a class and its subclass (or superclass) is called generalization or specialization. Subclasses inherit attributes and operations from their class. A subclass has its own additional attributes and operations. For example, the class SalesOrderCreditPmt inherits the attributes order No, order Date, delivery Date, and order Terms and the methods calcTotal and changeDelivDate. In this case, the class SalesOrder is the generalized class, and SalesOrderCheckPrmt and SalesOrderCreditPrmt are the specialized classes.6. PolymorphismEarlier it was mentioned that a DVR and a DVD player that respond similarly but differently to the same message are polymorphic. Polymorphism means “having many forms”. In the context of OQSAD, polymorphism means that the same message caninvoke similar but different behavior. Thus, a message that invokes the operation calcTotalQ of a :SalesOrder object will result in the sales order total calculation; a message that invokes the operation calcTotaIQ of a PurchaseOrder object will result in a purchase order total calculation. The implementation of the operations in the respective classes will be different.Foundations of the object modelStructured design methods evolved to guide developers who were trying to build complex systems using algorithms as their fundamental building blocks. Similarly, object-oriented design methods have evolved to help developers exploit the expressive power of object-based and object- oriented programming languages, using the class and object as basic building blocks. Foundations of the object model.Actually, the object model has been influenced by a number of factors, not just object-oriented programming. The object model has proven to be a unifying concept in computer science, applicable not just to programming languages but also to the design of user interfaces, databases, and even computer architectures. The reason for this widespread appeal is simply that an object orientation helps us to cope with the complexityinherent in many different kinds of systems.5。
测控技术与仪器专业英语翻译 殷虹 河北工业大学适用
测控专业英语翻译Unit1Measurement,ControlandInstrumentation Instrumentati on is defined as the art and science of measurement and control.Instrumentation engineers are responsible for controlling a whole system like a power plant.译为：仪器可定义为测量和控制的艺术和科学。
仪器工程师负责控制整个系统，比如一个电厂。
An instrument is a device that measures and/or regulates process variables such as flow, temperature, level, or pressure. Instruments include many varied contrivances that can be assimple as valves and transmitters, and as complex as analyzers.译为：仪器是一种用来测量和/或调节过程变量（如流量、温度、液位或压力）的装置。
仪器包括许多不同的设备，可以像阀和变送器那样简单，也可以像分析仪那样复杂。
Instruments often comprise control systems of varied processes such as refineries, factories,and vehicles. The control of processes is one of the main branches of applied instrumentation. Instrumentation can also refer to handheld devices that measure some desired variable.Diverse handheld instrumentation is common in laboratories, but can be found in thehousehold as well. For example, a smoke detector is a common instrument found in mostwestern homes.译为：仪器通常由如精炼厂、工厂和车辆这些不同流程的控制系统组成。
测控技术与仪器专业英语unit
全句译为：然而，供应电压从5V衰减到3.3V甚至更低， 以及系统中多种电压形式的出现，并不只是对最智能的传 感器提出的考验。
Separate integrated circuits (ICs) are available to handle the variety of voltages and resolve the problem, but they add to system and sensor complexity. 译为：单独的集成电路（ICs）可用来处理各种不同的电压 并解决问题，但它们增加了系统和传感器的复杂ors
Some of those same semiconductor manufacturers are actively working on smarter silicon devices for the input and output sides of the control system as well. The term microelectromechanical system (MEMS)（微机电系统） is used to describe a structure created with semiconductor manufacturing processes for sensors and actuators.
译为：在今天几乎一切的技术领域都将智能一词作为 其前缀的候选。智能传感器这一术语是在20世纪80年代 中期出现的，从那以后，一些设备已被称之为智能传感器。
3
Unit3 Smart Sensors
The intelligence required by such devices is available from microcontroller unit (MCU), digital signal processor (DSP), and application-specific integrated circuit (ASIC) technologies developed by several semiconductor manufacturers.
测控技术与仪器专业英语课文翻译单元1
测控技术与仪器专业英语课文翻译单元1Instrumentation is defined as the art and science of measurement and control. Instrumentation engineers are responsible for controlling a whole system like a power plant. 译为：仪器可定义为测量和控制的艺术和科学。
仪器工程师负责控制整个系统，比如一个电厂。
An instrument is a device that measures and/or regulates process variables such as flow, temperature, level, or pressure. Instruments include many varied contrivances that can be as simple as valves and transmitters, and as complex as analyzers. 译为：仪器是一种用来测量和/或调节过程变量（如流量、温度、液位或压力）的装置。
仪器包括许多不同的设备，可以像阀和变送器那样简单，也可以像分析仪那样复杂。
Instruments often comprise control systems of varied processes such as refineries, factories, and vehicles. The control of processes is one of the main branches of applied instrumentation. Instrumentation can also refer to handheld devices that measure some desired variable. Diverse handheld instrumentation is common in laboratories, but can be found in the household as well. For example, a smoke detector is a common instrument found in most western homes. 译为：仪器通常由如精炼厂、工厂和车辆这些不同流程的控制系统组成。
测控技术与仪器专业英语翻译
Selected from “Introduction to Control System technology , 4th Ed. , by Robert N. Bateson, Macmillan Publishing Co., 1933”. 选自“控制系统技术，第四版的介绍，罗伯特N.贝特森，麦克米兰出版有限公司，1933。
• 测量变量（CM）是衡量价值的控制变量。这是输出的测 量手段和通常不同于实际的控制变量的一小部分。
• The error (E) is the difference between the setpoint and the measured value of the controlled variable . It is computed according to the equation E=SP-.
控制变量（C）是过程的输出变量，用来出变量,它能很好地衡量 产品的质量。最常见的控制变量有位置、速度、温度、压 力和流量水平。
•
•
The set point (SP) is the desired value of the controlled variable.
6.Variable Name（变量名称）
•
The controlled variable (C) is the process output variable that is to controlled. In a process control system, the controlled variable is usually an output variable that s a good measure of the quality of the product. The most common controlled variables are position, velocity, temperature, pressure level and flow rate.
测控技术与仪器专业毕业设计外文翻译
测控技术与仪器专业毕业设计外文翻译Development of Sensor New TechnologySensor is one kind component which can transform the physical quantity,chemistry quantity and the biomass into electrical signal. Theoutput signalhas the different forms like the voltage, the electric current, the frequency, thepulse and so on, which can satisfy the signal transmission, processing,recording, and demonstration and control demands. So it is the automaticdetection system and in the automatic control industry .If automatic Technology is used wider, then sensor is more important.Several key words of the sensor:1 Sensor ElementsAlthough there are exception ,most sensor consist of a sensing element and aconversion or control element. For example,diaphragms,bellows,strain tubes andrings, bourdon tubes, and cantilevers are sensing elements which respond to changesin pressure or force and convert these physical quantities into a displacement. Thisdisplacement may then be used to change an electrical parameter such as voltage,resistance, capacitance, or inductance. Such combination of mechanical and electricalelements form electromechanical transducing devices or sensor. Similar combinationcan be made for other energy input such as thermal. Photo, magnetic andchemical,giving thermoelectric, photoelectric,electromaanetic, and electrochemicalsensor respectively.2 Sensor SensitivityThe relationship between the measured and the sensor output signal is usuallyobtained by calibration tests and is referred to as the sensor sensitivity K1= output-signal increment / measured increment . In practice, the sensor sensitivity is usuallyknown, and, by measuring the output signal, the input quantity is determined from input= output-signal increment / K1.3 Characteristics of an Ideal SensorThe high sensor should exhibit the following characteristics.(a)high fidelity-the sensor output waveform shape be a faithful reproduction of themeasured; there should be minimum distortion.(b)There should be minimum interference with the quantity being measured; thepresence of the sensor should not alter the measured in any way.(c)Size. The sensor must be capable of being placed exactly where it is needed.文献 (d)There should be a linear relationship between the measured and the sensor signal.(e)The sensor should have minimum sensitivity to external effects, pressure sensor,forexample,are often subjected to external effects such vibration and temperature.(f)The natural frequency of the sensor should be well separated from the frequencyand harmonics of the measurand.Sensors can be divided into the following categories:1 Electrical SensorElectrical sensor exhibit many of the ideal characteristics. In addition they offerhigh sensitivity as well as promoting the possible of remote indication ormesdurement.Electrical sensor can be divided into two distinct groups:(a)variable-control-parameter types,which include:(i)resistance(ii)capacitance(iii)inductance(iv)mutual-inductance typesThese sensor all rely on external excitation voltage for their operation.(b)self-generating types,which include(i)electromagnetic(ii)thermoelectric(iii)photoemissive(iv)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 sensor 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 sensor exhibits the reversible effect by deforming or vibrating at the frequency of the alternating voltage.2 Resistance SensorResistance sensor 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-circuitmethods. Examples of this group include strain gauges and resistance thermometers.文献3 Capacitive SensorThe capacitance can thus made to vary by changing either therelative 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 sensor has an infiniteresolution making it most suitable for measuring small increments of displacement orquantities which may be changed to produce a displacement.4 Inductive SensorThe inductance can thus be made to vary by changing the reluctanceof the inductive circuit.Measuring techniques used with capacitive and inductive sensor:(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 sensor are as follows: (i)resolution infinite(ii)accuracy?0.1% of full scale is quoted(iii)displacement ranges 25*10-6 m to 10-3m(iv)rise time less than 50us possibleTypical measurands are displacement, pressure, vibration, sound, and liquid level. 5 Linear Variable-differential Ttransformer6 Piezo-electric Sensor7 Electromagnetic Sensor8 Thermoelectric Sensor9 Photoelectric Cells10 Mechanical Sensor and Sensing ElementsIn information age, the information industry includes information gathering, transmission, process three parts, namely sensor technology, communication, computer technology. Because of ultra large scale integrated circuit’s rapid development aft er having been developed Modern computertechnology and communication, not only requests sensor precision reliability,文献speed of response and gain information content request more and more high but also requests its cost to be inexpensive. The obvioustraditional sensor is eliminated gradually 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 research and the development, and all has obtainedthe enormous breakthrough. Now the sensor new technology development mainly has following several aspects:Using the physical phenomenon, the chemical reaction, the biological effect as the sensor principle therefore the researches which discovered the new phenomenon and the new effect are the sensor technological improving ways .it is important studies to developed new sensor’s the foundation. JapaneseSharp Corporation uses the superconductivity technology to develop successfully the high temperature superconductivity magnetic sensor and get the sensor technology significant breakthrough. Its sensitivity is so high and only inferior in the superconductivity quantum interference component. Itsmanufacture craft is far simpler than the superconductivity quantum interference component. May use in magnetism image formation technology. So it has the widespread promoted value.Using the immune body and the antigen meets one another compound when the electrode surface. It can cause the electrode potential change and use this phenomenon to be possible to generate the immunity sensor. The immunity sensor makes with this kind of immune body may to some organism in whether has this kind of ant original work inspection. Likemay inspect somebody with the hepatitis virus immune body whether contracts the hepatitis, plays to is fast, the accurate role. The US UC sixth branch has developed this kind of sensor.The sensor material is the important foundation for sensor technology, because 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 thin film; The optical fiber can make the pressure, the current capacity, the temperature, the displacement and so on the many kinds of sensors; Making the pressure transmitter with the ceramics. The high polymer can become the proportion adsorption and the release hydrogen along with the environment relative humidity size. The high polymer electricity lies between文献the constant to be small, the hydrogen can enhance the polymer the coefficient of dialectical loss. Making the capacitor the high polymer dielectric medium, determines the electric capacity cape 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; Thesize 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 performance is stable, the year drifting quantity is smaller than 0.1%F.S, warm floats is smaller than ?0.15%/10K, anti- overloads strongly,may reach the measuring range several hundred times. The surveyscope may from 0 to 60mpa.German E+H Corporation and the American Kahlo Corporation product is at the leading position.The optical fiber application is send the material significant breakthrough, its uses in most early the optical communication techniques. In the optical communication use discovered works as environmental condition change and so on the temperature, pres-sure, electric field, magnetic field, causes the fiber optic transmissionlight wave intensity, the phase, the frequency, changeand so on the polarization condition, the survey light wave quantity change, may know causes these light wave physical quantity the and so on quantitative change temperature, pressure ,electric field, magneticfield size, uses these principles to be possible to develop the optical fiber sensor. The optical fiber sensor and the traditional sensor compare has many characteristics: Sensitivity high, the structure simple, the volume small, anti- corrosive, the electric insulation good, thepath of rays may be curving, be advantageous for the realization telemeter and so on. Optical fiber sensor Japan is in the advanced level.Like Idec Izumi Corporation and Sun x Corporation. The optical fiber send receiver and the integrated path of rays technology unify, accelerates the optical fiber sensor technology文献development. Will integrate the path of ray’s component to replace theoriginal optics part and the passive 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.In semiconductor technology processing method oxygenation, the photo etc hang, the proliferation, the deposition, the plane electron craft, various guides corrosion and steams plates, the sputtering thin film and so on, these have all introduced to the sensor manufacture. Thus has produced each kind of new sensor, like makes the silicon micro sensor using the semiconductor technology, 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 transmitter and so on..The Japanese horizontal river company uses various guides’corrosiontechnology to carry on the high accuracy three dimensional processing; the system helps the silicon resonance type pressure transmitter. The core partially presses two resonant Liang by thefeeling which above the silicon diaphragm and the silicon diaphragm manufactures to form, two resonant Liang's frequency difference correspondence different pressure, measures the pressure with thefrequency difference method, may eliminate the error which factor and so on ambient temperature brings. When ambient temperature change, two resonant Liang frequencies and the amplitude variation are same, after two frequency differences, its same change quantity can counterbalance mutually. It’s 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 the material, has the unique three dimensional structure, the light slight machine-finishing, makes the wheat stone bridge many times with the etching on the silicon diaphragm, when above silicon chip stress, it has the distortion, the resistance produces presses the anti- effect but to lose the bridge balance, the output and the pressure becomes the proportion theelectrical signal.Such silicon micro sensor is the front technology which now the sensor develops, Its essential feature is the sensitive unit volume is a micron文献magnitude, Is the traditional sensor several dozens, several 1%. In aspect and so on industry control, aerospace domain, biomedicine has the vital role, like on the airplane the use may reduce the airplane weight, reduces the energy. Another characteristic is can be sensitiveis small surveyed, may make the blood pressure pressure transmitter.The Chinese aviation main corporation Beijing observation andcontrol technical research institute, the development CYJ series splashes thanks the membrane pressure transmitter is uses the ion sputtering craft to process the metal strain gauge, it has over come the nonmetallic strain gauge easily the temperature influence 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 glue the precision which the type brought, sluggish big, shortcoming and so on slow change, had the precision high, the re-liability is high, the volume small characteristic, widely used in domain and so on aviation, petroleum, chemical industry, medical service.Integrates 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 and send the part will integrate on together the chip, will cause it to have the calibration, to compensate, from the diagnosis and the network correspondence function, it might reduce the cost, the gain in yield, this kind of blood pressure sensor which American LUCAS, NOVASENSORCorporation will develop, each week will be able to produce 10,000.The intellectualized sensor is one kind of belt microprocessor sensor, is achievement which the microcomputer and the sensor unifies,it has at the same time the examination, the judgment and the information processing function, compares with the traditional sensor has very many characteristics:Has the judgment and the information processing function, can carry on the revision, the error to the observed value compensates, thus enhancement measuring accuracy; May realize the multi-sensor multi parameters survey; Has from the diagnosis and from the calibration function, enhances the reliability; The survey data may deposit and withdraw, easy to operate; Has the data communication interface, can and the microcomputer direct communication.文献 The sensor, the signal adjustment electric circuit, the monolithic integrated circuit integration forms ultra large-scale integrated on a chip the senior intelligence sensor. American HONY WELL Corporation ST-3000intelligence sensor, the chip size only then has 3×4×2mm3, usesthesemiconductor craft, makes CPU, EPROM, the static pressure, the differential pressure, the temperature on the identical chip and so on three kind of sensitive units.The intellectualized sensor research and the development, US is at the leading position. American Space Agency when development spaceship called this kind of sensor for the clever sensor (Smart Sensor), on the spaceship this kind of sensor is extremely important. Our country inthis aspect research and development also very backward mainly is because our country semiconductor integrated circuit technological level is limited.The sensor’s development is changing day after day since especially the80's humanities have entered into the high industrialization the information age, sensor techno-logy to renewal, higher technological development. US, Japan and so on developed country sensor technological development quickest, our country because the foundation is weak, the sensor technology compares with these developed countries has the big disparity. Therefore, we should enlarge to the sensor engineering research, the development investment, causes our country sensor technology and the foreign disparity reduces, promotes our country instrument measuring appliance industry and from the technical development.,Jon ——From《Sensor Technology Handbook》Wilson,Newnes文献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。
测控技术与仪器专业英语词汇
Lesson 1Accuracy 精确性、精度Amplitude 振幅，幅度Channel 信道，频道Coefficient 系数Convergence 收敛Differentiate 求……的微分Expansion 展开式Harmonic 谐波的Instant 瞬时，时间Integrate 求……的积分Linear 线性的Order 次序，阶Peak 最高的，最高峰Periodicity 周期Phase 相位Polynomial 多项式的，多项式Resistor 电阻器Series 展成级数，级数Taylor series 泰勒级数Set 集合Sinusoidal 正弦的Time domain 时域frequency-domain 频域integrand 被积函数Lesson 2decay 衰减duration 持续时间exponential 指数的multiplier 乘数，乘法器oscillatory 振荡的frequency density function 频率密度函数Fourier series 傅立叶级数Spectrum 频谱Imaginary part of complex 复数的虚部Real part of complex 复数的实部Conjugate pairs 共轭对Lesson 3algorithm 算法decaying oscillatory function 衰减振荡函数power series 幂级数shift operator 移位算子product 乘积electrical disturbance 电干扰sampled-data signal 数据采样信号be proportional to 与…成正比Lesson 5dead-band 死区hysteresis 滞后linearity 线性度measurand 被测量oscilloscope 示波器performance 特性precision 精确度resolution 分辨率static friction 静态摩擦sensitivity 灵敏度calibration 校准loading effect 负载效应slop 斜率platinum 铂thermometer 温度计in cascade with 与…串联in parallel with 与…并联lever 杠杆displacement 位移indicated value示值true value 真值deflection 偏转possible error 可能误差probable error 概率误差root-sum-square error 方和根误差Lesson 6overshoot 过调量，超调量transient response 瞬态响应variable 变量ramp 斜坡resonance 共振step input 阶跃输入step response 阶跃响应transient 瞬态的first-order system 一阶系统static error 静态误差dynamic error 动态误差time constant 时间常数frequency response 频率响应damping ratio 阻尼比under-damp 欠阻尼over-damp 过阻尼mass-spring system 质量-弹簧系统steady-state 稳态rise time 上升时间settling time 建立时间（过渡过程时间）specification 性能指标tolerance 容差Lesson 7capacitance 电容deformation 变形distortion 变形，扭曲electromagnetic 电磁的gauge 表，仪器，计strain gauge 应变计crystalline material 晶体材料voltage 电压current 电流harmonics 谐波inductance 电感，感应infrared 红外的linearize 线性化natural frequency 固有频率mutual-inductance 互感photoconductive cell 光电导管photoelectric effect 光电效应piezo-electric 压电的potential divider 分压器potentiometer 电位计，电位器精品文库resistance 电阻thermistor 热敏电阻transducer 转换器，传感器cross-sectional area 截面积excitation voltage 激励电压full-scale 满量程rotary 旋转的translational 平移的mechanical wear 机械磨损inertia 惯性power dissipation 功耗illumination 照度transparent 透明的Lesson 8coupling 耦合flux 磁通impedance 阻抗permeability 磁导率permittivity 电容率，介电系数reluctance 磁阻variable-distance capacitive transducer 变间距式电容式传感器oscillation circuit 振荡电路l.v.d.t 线性差动变压器piezo-electric transducer 压电式传感器charge amplifier 电荷放大器parallel-plate capacitor 平板电容器variable-reluctance transducer 变磁阻传感器liquid level 液位Lesson 9apparatus 仪器attenuator 衰减器bandwidth 带宽battery 电池be inversely proportional to 与成反比be proportional to 与成正比capacitor 电容feedback 反馈gain 增益operational amplifier 运算放大器semiconductor 半导体terminal 终端test probe 探针voltmeter 电压表multirange 多量程variable resistor 可变电阻Lesson 10duty cycle 占空比timerbase 时基register 寄存器signal conditioning 信号调理threshold 阈值trigger 触发器Lesson 11adapter boarder 适配板analog-to-digital conversion模数转换desktop 工作平台distortion 失真dynamic 动态的expansion slot 扩展槽generator 发生器interface 接口local area network LAN 局域网motherboard 母板scale 刻度slot 长槽workbench 工作台computer-aided testing（CAT）计算机辅助测试desktop personal computer台式个人计算机knob 旋钮16-channel analog-to-digitalconversion board 16通道模/数转换板12-bit resolution 12位分辨率buffer 缓冲器interface 接口data-gathering device 数据采集装置Lesson 12active element 有源元件bias 偏差，偏置current intensity 电流electrode 电极field-effect transistor FET场效应管grid 格子，栅极integrated circuit 集成电路magnetic field 磁场passive component 无源元件photocell 光电管sensor 传感器，敏感元件thermocouple 热电偶transducer 变换器，换能器，传感器vacuum tube 真空管，电子管Lesson 13cache memory 高速缓冲存储器，高速缓存control unit 控制器，控制部件drain 场效应管的漏集dynamic RAM （DRAM）动态随机存取存储器gate 门（电路），管子的栅极local memory 局部存储器，本地存储器metal-oxide-semiconductorfield effect transistor（MOSFET）金属氧化物半导体场效应管microcontroller 微控制器microprocessor微处理器monitor 监视器mouse 鼠标精品文库printer打印机static RAM （SRAM）静态RAMultra-large-scale integratedcircuit 超大规模集成电路。
测控技术与仪器专业英语课文以及单词
? One can measure thickness on many scales .The galaxy is sphick.. 你可以测量厚度,在许多尺度螺旋星系的约100 Em(1020m磁盘)深
? 3.Distance measurement 3。距离测量
? The tools and techniques of distance measurement are possibly one of humankind's longest-running inventive pursuits .This chapter concerns itself with methods to measure a relatively small segment of this range-from centimeters to kilometers .Even within this limited segment ,it would hardly be possible to list ,much less describe ,all of the distance measurement approaches that have been devised .Nevertheless ,the small sampling of technologies that are covered here should be of help to a broad range of readers.
? The altitude information at air traffic control (ATC) centers is based on pressure altitude measurement that the aircraft transponder system sends after it receives an appropriate interrogation——known as mode C interrogation——transmitted by a secondary surveillance radar. Actually, the altitude information is an atmospheric pressure measurement transformed to altitude indication through a formula expressing the pressure/altitude relationship. When a flight level is cleared for an aircraft, it actually means that the pilot must keep flying on an isobaric surface. However, the altimetry system may present systematic errors (biases) that are different for each airplane, and that significantly affect safety. Thus, the altimetry system performance as well as the aircraft height keeping performance must be monitored by an independent radar or satellite system. 信息的高度,在空中交通管制中心(ATC)根据压高度测量,飞机的应答机系统发给后都把它珍藏一个适当的审讯——被称为模式C讯问——通过二级监视雷达。实际上,高度的大气压力测量信息转化为高度通过公式显示表达压力/高度的关系。当一个飞行高度是允许飞机时,实际上就意味着飞行员必须不停地飞在一个isobaric表面。然而,altimetry系统系统误差可能出现偏差)(飞机的不同而有所区别,明显影响安全。因此,altimetry系统性能以及飞机高度保持性能均须由独立的雷达或卫星电视系统
测控技术与仪器专业英语单词总结
Operational description 操作描述；Acquisition of information 信息采集；Object of measurement 测量目标；Measurand 被测物理量；Measurement result 测量结果；A necessary and not a sufficient aspect 一个必要而非充分的条件Selectivity 选择性；Objective 客观的Observer 观察者；观察器Extract 吸取，摘取Arbitrary 专横的，专断的，反复无常的；Conclusion 结论；Highly subjective 高度主观的；Handicapped 残疾的Magnetic field 磁场Objectivity 客观性Artefact 人工品Misinterpret 曲解Measurement instrument's output 测量装着的输出；Structural information 公制信息Qualitative measurement 质量测量Quantitative measurement 数量测量Nature 本质Respective characteristic 各自的特性Empirical world 经验的世界Abstract image 抽象的映像Actual empirical quantity 实际经验的数量Mapping of element 元素的映射Source set 源集Empirical domain space 经验域空间Image set 映像集Abstract range space 抽象域空间Electrical domain 电气域Measurement process 测量过程Symbol 符号Assignment algorithm 分配算法Abstract symbol 抽象符号Employed measurement system 被使用的测量系统Descriptive 描述的，叙述的Set theory 集合论Relational system 相关系统Physical quantity 物理量Electrical potential difference 电势差Cardinal measurement 最重要的测量Jolt 重击，摇撼Mutual induction 互感Quotient 商数Thermostat 自动调温器Coil 线圈Alloy 合金Geometry 几何学，几何，几何图形，几何结构Coaxial 同轴的，同轴电缆的Cylinder 圆柱体，汽缸，圆柱形的容器Parasitic quantity 寄生量附属量Interaction 互交作用Isolated measurement 隔离测量，独立测量Inanimate 死气沉沉的，没生命的，单调的Practicable 能实现的行得通的，可以实行的Sake 为了...的好处，出于对...的兴趣，缘故，理由Conduct 引导，传到Consumer goods 消费商品Scarcity 缺乏，不足Extent 范围，程度Obscure 使暗，使不明显Corrupt 使恶化Sensitivity 敏感，灵敏，灵敏性Repetition 重复性Reproducible 能繁殖的，可再生的，可复写的Random errors 随机误差Ethical 与伦理有关的，民族的，民族特有的Modified variable 修改变量Irreversible process 不可改变的进程Psychological experiment 心里测试Catatonic state 紧张性神经病的状态Mental disorder 精神错乱Chronic schizophrenia 慢性精神分裂症Oscilloscope 示波器，示波管Rms 均方根Ferric 铁的，含铁的Chloride 氯化物漂白粉Measurement strategy 测量策略fluctuate 波动frequency spectrum 频谱coherent sampling 相干采样periodic 周期的，定期的Sample 采样值actual measurement signal 实际测量信号denote 表示skipped period 跳跃区间Reconstructed signal 重建的信号envelope 包络线Peak 最高值，峰值sampling oscilloscope 采样示波器arbitrary moment 任意时刻amplitude distribution function 振幅分布函数statistical parameter 统计参数Multiplex 多路操作Simultaneously 同时地sequentially 顺序地time multiplexing 时间多重操作Enumeration 计数，列举，细目Analogy 类推，类比，类推法Repetition 重复，循环Denote 指示，标志Stroboscopic 频闪观测仪scatter 使分散，驱散，散布，挥霍，消散，溃散nonlinearity 非线性，非直线性discernible 可辨别的，可看出的class 分类systematic errors 系统误差random errors 随机误差consistently 固守地一贯地inaccurate calibration 不准确的刻度mismatched impedance 不匹配的阻抗response-time error 反应时间误差malfunction 故障障碍，发生故障oscillator 振荡器。
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附录外文文献翻译本文将简要介绍接触角的应用和测量技术。
主要讨论并比较了这两种测量技术。
什么是接触角？接触角θ是用来定量表征液体对固体的润湿性。
如下面的几何图形所示，接触角是由固体、液体、气体三相边界组成的，有液体一侧到固体部分的角度。
从图中可以看出：接触角θ的值小，则表明液体铺展或者润湿性好。
而接触角θ的值较大，则表明润湿性较差。
如果接触角θ小于90度，也就是说，液体浸润固体，如果接触角的值大于90度，就是说不浸润，而0度接触角表明完全润湿。
用一个单独的静态接触角来表征界面间的相互影响还不是太充分。
对于任意给定的液固界面，总可以一系列存在的接触角。
人们发现，静态接触角的值取决于液固界面的相互影响。
人们把液滴铺展的接触角称为“前进接触角”，而把缩小的接触角称为“后退接触角”。
前进接触角接近于最大值，后退接触角接近于最小值，而这一系列角的值就在这最大值和最小值之间。
在实际运动中，三相(液体、固体、气体)边界产生的角称为动态接触角，也可以指“前进的”和“后退的”的角。
“前进的”和“在前进的”或“后退的”和“在后退的”区别在于在静态运动的开始实际上是动态的。
动态接触角是在各种比率的速度下测定的，在较低的速度下测定的动态接触角应该是静态接触角相等。
滞后现象最大的（前进的/在前进的）和最小的（后退的/在后退的）接触角之间的差值就是接触角的滞后现象。
已经有大量的研究分析了接触角滞后现象的意义。
它通常用来表征表面的多向性、粗糙性和活性。
简而言之，对于不均匀的表面，在表面上出现阻碍接触线移动的区域。
对于化学多向性这种情况，这些区域指的是比周围表面有不同接触角的区域。
下面以水润湿为例，当液体前进而接触角的增加，憎水区域将锁定接触线。
当水从亲水区域退湿时，将阻碍接触线的移动，而减小接触角。
从这些分析中可以看出，用水测试时，前进接触角对憎水区敏感，而后退接触角表征了表面亲水区的特征。
表面粗糙性产生接触角的滞后现象，在这种情况下，显微镜的实际倾斜度的变化在固体表面产生了障碍。
这种障碍锁定了接触线的移动和改变了宏观的接触角。
大量的研究显示了接触角的滞后现象，从文章后的引用文献中可以得到更详细的讨论。
接触角也可以从所涉及的材料的热力学形式考虑。
这种分析涉及到三种相态的界面自由能，如下面的公式所示：σlv cosθ=σsv-σsl式中：σlv ,σsv和σsl分别是液-气、固-气和固- 液界面的界面能。
如何测量接触角？测角法和张力测定法是两种不同的用来测量少孔固体表面的接触角的方法。
测角法涉及到固体底面上测试液的固定液滴的观测，张力法涉及到测量固体和测试液体接触的相互作用力。
两种方法在下面的文章中介绍，对于个别的研究而选择任何一种。
一种方法通常用于多孔固体粉末、织物的情况下，这种技术用到张力计，例如：KSV标准差70和Washburn方法。
样品中含有吸收润湿液体的多孔结构时，宜选用这种方法。
下面的文章中将简要的描述并在参考文献104中有更多详细的介绍。
测角法分析置于固体上测试液体的形式是测角法的基础。
测角法的基本组成包括光源、试样平台、透镜和图像采集卡。
接触角由直接测量固体和液滴表面的切线之间的角度来估计。
两种方法的其中之一就产生液滴前进和后退边缘。
通过增加液体而使液滴产生前驱边缘。
而通过是液滴蒸发或者从液滴中抽取液体产生后退边缘。
当液体处于起始运动的阶段就产生了前进或者后退边缘。
运用具有高速图像采集能力的设备就能分析运动液滴的形状了。
KSV提供了两种测量接触角的设备：CAM100和CAM200。
CAM100应用了50毫米的USB摄像头捕捉图像，CAM200应用了高速的CCD摄像机捕捉图像，而后，图像用计算机软件分析。
优点测角法用于张力法不能用的情形下。
人们使用的各种固体底面。
底面上总有一个相对平坦的用于测试的部分，这部分适合于设备的平台。
对有规则曲线的地面摄像，也容易分析。
这种设备只适用于非常少量的液体，对于聚合物这样的高温液体也容易测量。
缺点接触角切线的作法是减少接触角测量可重复性的一个因素，而接触角的切线将能确定接触角。
简易的测角法取决于在切线作法上操作者的一致性。
这可能导致较大的错误，特别是操作者多次使用的主观性的错误。
KSV设备中的CAM100和CAM200通过使用计算机分析液滴形状来消除这个问题，而得到接触角的数据。
有时候，这种情况产生的前进接触角和后退接触角很难有可重复性。
尽管从运动中的液滴得到了关于动态接触角的数据，但是运动速度不能控制，相对于后面介绍的张力法，测角法还是不太适合于通过润湿作用对接触角的分析。
另外，由于每次测量中液体的数量受到限制，应该多次测量来表征表面的特性，测角法还不能用于研究纤维。
张力法固体试样与测试液体接触，用张力测量法测量接触角，而且测量它们之间存在的张力。
如果知道了相互影响的作用力、固体的几何形状、液体的表面张力就可以计算出来接触角了。
使用者首先用Wihelmy插板法和Dunouy吊环法测量液体的表面张力，这时被测固体试样需要平衡悬挂，叶面上升接触到固体。
当二者接触后，可以探测到作用力的改变。
而没有浸没时标准差记录下了这种上升。
也记录下了当固体置入液体平衡时的作用力，平衡作用力可用下式表示：Ft=润湿力+探头力-浮力Sigmn70表明了探头的自重，从未浸没时地图线中可以推断浮力作用的影响。
剩下的那部分作用力就是如下是定义的润湿力：润湿力=pσl-v cosθ公式中，σl-v是液体的表面张力，p是探头的周长，θ是接触角，因此可以用来计算任何深度的接触角。
这个接触角是探头进入液体而产生的接触角，固体试样浸没到一定的深度。
与此过程相反，随着探头从液体中抽出，可以用来测量后退接触角。
优点应用张力法测量液体的接触角比测角法有几个优势，对于浸没曲线上的任何一点，任何深度的固体的圆周上的所有点都可以利用。
因此任一给定的浸没深度上都可以用来计算接触角的作用力是一个平均值。
可以用来计算试样整个长度上的平均值或者任何一部分浸没曲线上的平均值来测定沿着试样长度上的接触角的改变。
这项技术要求试验者分析接触角的值，而这个接触角是由静态到迅速润湿的过程中，在整个范围内的润湿而产生的。
因为接触角取决于一种力，而这个力是由没有主观错误可能性的设备测量出来的。
接触角的变化包括前进接触角和后退接触角，而这些在同一条曲线上都可以看到。
另外，由重复润湿产生的变化能够得到由润湿引起的接触角变化的信息，但使用测角法很难分析纤维，而用测力法就很容易。
缺点这种技术的应用有两个方面的缺陷，首先，试验者需要有足够的可以利用的测试液，以便可以浸没固体试样的任何一部分。
其次，被测固体下次还可以再利用，要求固体试样制作成形或者是有规则的几何外形。
这样就有占其长度一定部分的周长了。
我们知道的杆状物、平板、纤维的周长都是理想的。
与液体接触的固体试样所有面都必须有相同的表面，试样的量也必须足够的小，以便在Singma70上悬挂时达到平衡。
这种技术更难在高温的测量系统中使用，温度低于或者等于100度时，很容易处理。
而超过了这个范围的测量另外讨论。
Washburn法若待测固体试样是多孔结构时，产生了润湿液的吸收，可以选择这种方法。
固体与测试液体接触后，随着时间的改变，测试固体吸收了大量的液体。
吸收量是粘滞度、密度、液体的表面张力作用、固体材料的系数和接触角相互影响的结果。
如果粘滞度、密度和表面张力已知，那么材料系数和接触角就能够求出来。
KSV仪器借助于Washburn法提供了两种寻找接触角的手段，Sigma70和LPR902。
从参考文献104中可以得到详细的介绍。
接触角的应用接触角研究的主要焦点是固液界面相互作用的润湿特性。
接触角通常用于润湿性的直接测量，而其他的实验参数可以从接触角和表面张力中推导出来。
举例如下：黏附功:定义黏附功时，要求区分液体和固体的相面或者负面自由能与固体和液体相面的黏附功，它们也要联系在一起。
用来表示两种相面的相互作用力，由下面的Young-Dupre等式：Wa=σ(1+cosθ)内聚功：定义内聚功时，要求把液体分为两部分，测量液体内部的相互作用为下面的等式：Wc=2σ铺展功：负自由能与液体在固体表面的铺展联系起来，由下式给出：Ws=σ(cosθ-1)润湿张力：如下是定义，张力大小：τ=F w/P=σLV cosθ这个值是润湿张力对长度的标准化，也表示接触角的余弦值和表面张力的乘积。
在没有表面张力的独立测量中，考虑到润湿作用力的特性，在某些情况下还是有意义的，而在多组合系统中，界面的表面张力可能不等于平衡时的表面张力，因此这里也指黏附功或者润湿功.表面张力的测量数据直接反映测试溶液的热力学特性。
接触角的测量数据反映液固相互作用的热力特性。
只需要知道特殊液固的接触角，就可以表征其润湿行为。
也可能用一种更普遍的方式表征固液间的润湿性。
可用的方法很多，但每一中方法的基本原理是相同的。
一种固体与多种液体相接触，可以测得多个接触角。
依据这些测量，计算就可以得到参数（临界表面张力、表面能），而这些参数量化了固体润湿的特性。
这里有两种基本的方法：临界表面张力：对于一系列不同表面张力的均匀液体用σ与cosθ做一张曲线图，会发现在一给定的σ下，cosθ的值接近于，这就对应着表面张力的最大值，也就是完全润湿，把这个值称为临界表面张力，通常用来表征固体的特性。
表面自由能：另一种表征表面张力的方法是通过计算自由表面能，也称为固体的表面张力。
这种方法涉及到测试液对固体有较好的润湿性，使用的液体润湿性要好那样他们的表面张力的极性和色散量已知，由Owens和Wendt给出的相关公式:σl (1+ cosθ)/(σld)1/2 =(σsp)1/2[(σlp)1/2/(σld)1/2]+(σsd)1/2式中的θ是接触角，σl 是液体的表面张力，σs固体的表面张力或自由能,另外，d和p分别是色散量和每一部分的极性。
等式的组成如下式的形式:y= m x+ b.能够作出(σlp )1/2/(σld)1/2和σl(1+ cosθ)/(σld)1/2图像，斜率为(σsp )1/2(σsd)1/2.是ym的截距，真个自由表面能基本上就是由他们这两种组成了。
This application note provides a brief introduction to the use and measurement ofcontact angles. The techniques used for measurement are discussed and compared. What is contact angle?Contact angle, θ, is a quantitative measure of the wetting of a solid by a liquid. It is defined geometrically as the angle formed by a liquid at the three phase boundary where a liquid, gas and solid intersect as shown below:It can be seen from this figure that low vathan 90 the liquid is said to wet the solid. If it is greater than 90 it is said to benon-wetting. A zero contact angle represents complete wetting.The measurement of a single static contact angle to characterize the interaction is no longer thought to be adequate. For any given solid/ liquid interaction there exists a range of contact angles which may be found. The value of static contact angles are found to depend on the recent history of the interaction. When the drop has recently expanded the angle is said to represent the ‘advanced’ contact angle. When the drop has recently contracted the angle is said to represent the ‘receded’ contact angle. These angles fall within a range with advanced angles approaching a maximum value and receded angles approaching a minimum value.If the three phase(liquid/solid/vapor) boundary is in actual motion the angles produced are called Dynamic Cont act Angles and are referred to as ‘advancing’ and‘receding’ angles. The difference between ‘advanced’ and ‘advancing’, ‘receded’ and ‘receding’ is that in the static case motion is incipient in the dynamic case motion is actual. Dynamic contact angles may be assayed at various rates of speed. Dynamic contact angles measured at low velocities should be equal to properly measured static angles.HysteresisThe difference between the maximum(advanced/advancing) and minimum (receded/receding) contact angle values is called the contact angle hysteresis. A great deal of research has gone into analysis of the significance of hysteresis. It has been used to help characterize surface heterogeneity, roughness and mobility. Briefly, for surfaces which are not homogeneous there will exist domains on the surface which present barriers to the motion of the contact line. For the case of chemical heterogeneity these domains represent areas with different contact angles than the surrounding surface. For example when wetting with water, hydrophobic domains will pin the motion of the contact line as the liquid advances thus increasing the contact angles. When the water recedes the hydrophilic domains will hold back the draining motion of the contact line thus decreasing the contact angle. From this analysis it can be seen that, when testing with water, advancing angles will be s e n s i t i v e t o t h e h y d r o p h o b i c d o m a i n s a n d r e c e d i n g angles will characterize the hydrophilic domains on the surface.For situations in which surface roughness generates hysteresis the actual microscopic variations of slope in the surface create the barriers which pin the motion of the contact line and alter the macroscopic contact angles. There has been a great deal of research investigating the significance of hysteresis and you are recommended t o t h e papers cited at the end of this note for further details.Contact angle can also be considered in terms of the thermodynamics of the materials involved. This analysis involves the interfacial free energies between the three phases and is given by:σlv cosθ=σsv -σslwhereσlv ,σsv andσsl refer to the interfacial energies of the liquid/vapor,solid/vapor and solid/liquid interfaces.How is contact angle measured?Two different approaches are commonly used to measure contact angles ofnon-porous solids, goniometry and tensiometry. Goniometry involves the observation of a sessile drop of test liquid on a solid substrate. Tensiometry involves measuring the forces of interaction as a solid is contacted with a test liquid. Both techniques are described below with comments on the choice of either technique for particular research applications.In the case of porous solids, powders and fabrics another approach is commonly used. This technique involves using a tensiometer, such as the KSV Sigma 70, and the Washburn method. It is the method of choice when your sample contains a porous architecture which absorbs the wetting liquid. It is described briefly below and more completely in Application Note # 104.GoniometryAnalysis of the shape of a drop of test liquid placed on a solid is the basis for goniometry. The basic elements of a goniometer include a light source, sample stage, lens and image capture. Contact angle can be assessed directly by measuring the angle formed between the solid and the tangent to the drop surface.The production of drops with advanced and receded edges involves one of two strategies. Drops can be made to have advanced edges by addition of liquid. Receded edges may be produced by allowing sufficient evaporation or by withdrawing liquid from the drop. Alternately, both advanced and receded edges are produced when thestage on which the solid is held is tilted to the point of incipient motion. Using an instrument with high speed image capture capabilities shapes of drops in motion may b e analyzed.KSV Instruments supplies two instruments for goniometry, the CAM100and CAM 200. The CAM100 uses a 50mm USB camera for image capture. The CAM200 instruments uses a high speed CCD camera for image capture. The images are analyzed with computer software.AdvantagesGoniometry can be used in many situations where tensiometry cannot. You can use a great variety of solid substrates provided they have a relatively flat portion for testing and can fit on the stage of the instrument. Substrates with regular curvature, such as contact lenses are also easily analyzed.Testing can be done using very small quantities of liquid. It is also easy to test high temperature liquids such as polymer melts.LimitationsThe assignment of the tangent line which will define the contact angle is a factor which can limit the reproducibility of contact angle measurements. Conventional goniometry relies on the consistency of the operator in the assignment of the tangent line. This can lead to significant error, especially subjective error between multiple users. KSV Instruments’CAM 200 and CAM100 remove this problem by using c o m p u t e r analysis of the drop shape to generate consistent contact angle data.The conditions which produce advanced and receded angles are sometimes difficult to reproduce. Although drops in motion can produce data on dynamic contact angles the velocity of motion cannot be controlled. It is also less suited, whencompared to tensiometry, to analysis of the effects of wetting on changes in contact a n g l e.In addition the amount of surface sampled for each measurement is limited and multiple measurements should be used to characterize a surface. Fibers are not easily studied by goniometry.TensiometryThe tensiometric method for measuring contact angles measures the forces that are present when a sample of solid is brought into contact with a test liquid. If the forces of interaction, geometry of the solid and surface tension of the liquid are known the contact angle may be calculated. The user first makes a measurement of the surface tension of the liquid using either a Wilhelmy plate or DuNouy ring. The sample of the solid to be tested is then hung on the balance and tared. The liquid is then raised to contact the solid. When the solid contacts the liquid the change in forces is detected and your Sigma70 registers this elevation as zero depth of immersion. As the solid is pushed into the liquid the forces on the balance are recorded. The forces on the balance areF total = wetting force + weight of probe - buoyancyYour Sigma70 has tared the weight of the probe and can remove the effects of the buoyancy force by extrapolating the graph back to zero depth of immersion. The remaining component force is the wetting force which is defined as:Wetting force = σLV P cosθwhereσLV is the liquid surface tension, P is the perimeter of the probe andθis the contact angle. Thus at any depth data is received which can be used to calculate contact angle. This contact angle, which is obtained from data generated as the probe advances into the liquid, is the advancing contact angle. The sample is immersed to a set depth and the process is reversed. As the probe retreats from the liquid data collected is used to calculate the receding contact angle.AdvantagesThe use of tensiometry for measurement of contact angle has several advantages over conventional goniometry. At any point on the immersion graph, all points along the perimeter of the solid at that depth contribute to the force measurement recorded. Thus the force useaveraged value. You may calculate an averaged value for the entire length of the sample or average any part of the immersion graph data to assay changes in contact a n g l e a l o n g t h e length of the sample.This technique allows the user to analyze contact angles produced from wetting over an entire range of velocities from static to rapid wetting. Because the contact angles are determined from the forces measured by the instrument there is no p o s s i b i l i t y o f subjective error.The graphs produced by this technique are very useful in studying hysteresis. Variations of contact angles, both advancing and receding, for the entire length of the sample tested is visualized on the same graph. In addition variations generated over multiple wetting/dewetting cycles can yield information on changes caused by wetting (such as absorption or surface reorientation).Analysis of fibers, very problematic for goniometry, is handled easily by your tensiometer.LimitationsThere are two major limitations for the application of this technique. Firstly the user must have enough of the liquid being tested available so that he can immerse a portion of his solid in it. Secondly the solid in question must be available in samples which meet the following constraints. The sample must be formed or cut in a regular geometry such that it has a constant perimeter over a portion of it’s length. Rods, plates or fibers of known perimeter are ideal. The sample must have the same surfaceon all sides which contact the liquid. The sample must also be small enough so that it c a n b e h u n g o n t h e microbalance of your Sigma70 .It is also more difficult to use this technique in systems which are measured at high temperatures. Temperatures at or below 100 C are easily handled but for measurements above this range goniometry is recommended.Wasshburd MethodThis method is chosen when the solid sample to be tested contains a porous architecture which leads to absorption of the wetting liquid. The solid is brought into contact with the testing liquid and the mass of liquid absorbed into the solid is measured as a function of time. The amount absorbed is a function of the viscosity, density and surface tension of the liquid, the material constant of the solid , and the contact angle of the interaction. If the viscosity, density and surface tension of the liquid are known the material constant and contact angle can be solved for. KSV instruments produces two instruments capable of finding contact angles via the W a s h b u r n t e c h n i q u e,t h e S i g m a70 and LPR 902. See Application Note #104 for details.Utilization of Contact Angle Data:The primary focus of contact angle studies is in assessing the wetting characteristics of solid/liquid interactions. Contact angle is commonly used as the most direct measure of wetting. Other experimental parameters may be derived directly from contact angle and surface tension results. Some examples are: Work of Adhesion: defined as the work required separating the liquid and solid phases, or the negative free energy associated with the adhesion of the solid and liquid phases. Used to express the strength of the interaction between the two phases. It is given by the Young-Dupre equation as:W a =σ( 1+cosθ)Work of Cohesion: defined as the work required to separate a liquid into two parts, it is a measure of the strength of molecular interactions within the liquid. It is given by;W c = 2σWork of Spreading: the negative free energy associated with spreading liquid over solid surface. Also referred to as Spreading Coefficient it is given as:W s =σ(cosθ- 1)Wetting Tension: a measurement of force/length defined as:τ=F w/P=σLV cosθThis value, wetting force normalized for length, also represents the product of the cosine of the contact angle and the surface tension. It allows for a characterization of the strength of the wetting interaction without separate measurement of surface tension. Most helpful in situations, such as multicomponent systems, where surface tension at interface may not equal equilibrium surface tension. Also referred to as A d h e s i o n Tension or Work of Wetting.Characterization of the Solid SurfaceMeasurements of surface tension yield data which directly reflect thermodynamic characteristics of the liquid tested. Measurement of contact angles yield data which reflect the thermodynamics of a liquid/solid interaction. If you wish to characterize the wetting behavior of a particular liquid/solid pair you only need to report the contact angle. It is possible to characterize the wettability of your solid in a more general way. Various methods are used but the same basic principle applies for each. The solid is tested against a series of liquids and contact angles are measured. Calculations based on these measurements produce a parameter(critical surfacetension, surface free energy,etc) which quantifies a characteristic of the solid which m e d i a t e s w e t t i n g.T w o b a s i c approaches are covered hereCritical Surface Tension: Using a series of homologous liquids of differing surface tensions a graph of cosθvs is produced. It will be found that the data form a line which approaches cosθ= 1 at a given value of σ. This is the maximal surface tension of a liquid which may completely wet your solid. This value, called the critical surface tension, can be used to characterize your solid surface. See r e f e r e n c e s f o r d e t a i l s o n procedure and limitations.Free Surface Energy: Another way to characterize a solid surface is by calculating free surface energy, also referred to as solid surface tension. This approach involves testing the solid against a series of well characterized wetting liquids. The liquids used must be characterized such that the polar and dispersive components of their surface tensions are known. The relevant equation is given by Owens and Wendt a s:σl(1+ cosθ)/(σld)1/2 =(σsp)1/2[(σlp)1/2/(σld)1/2]+(σsd)1/2 where θis the contact angle,σl is liquid surface tension and σs is the solid surface tension, or free energy. The addition of d and p in the subscripts refer to the dispersive and polar components of each. The form of the equation is of the type y = m x+ b. You can graph (σlp)1/2/(σld)1/2vsσl(1+ cosθ)/(σld)1/2 .The slope will be(σsp)1/2and the y-intercept will be (σsd)1/2. The total free surface energy is merely t h e s u m o f i t s two component forces.References:General:J.C.Berg, Wettability, Marcel Dekker,N.Y.(1993)M.E.Schrader,G.Loeb, Modern Approach to Wettability, Plenum Press N.Y.(1992) A.W.Adamson,Physical Chemisrty of Surfaces, Wiley & Sons,(1976)S.Wu, Polymer Interface & Adhesion, Marcel dekker,N.Y.(1982)J.D.Andrade in Surface & Interfacial Aspects of Biomedical Polymers,Vol 1, Plenum Press,N.Y.(1985)R.L.Bendure,J.Colloid Interface Sci.,42(1),137-144(1973)Hysteresis:L.W.Schwartz,S.Garoff,Langmuir, 1,219-230,(1985)J.H.Wang,P.M.Claesson,J.L.Parker,H.Yasuda,Langmuir,10,3887-3897(1994)R.E.Johnson,R.H.Dettre,J.Colloid Interface Sci, 62(2),205-212(1977)J.Drelich, Polish J. Chem,71,525-549(1997)Fibers:F.Hoecker, J.Karger-Kocsis, J Applied Polymer Sci.,59,139-153(1996)ler,L.Penn,S.Hedvat, Colloids & Surfaces, 6,49-61(1983)。