自动化专业外文文献

Development of Sensor New Technology

Sensor is one kind component which can transform the physical quantity, chemistry 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, and demonstration and control demands. So it is the automatic detection 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 Elements

Although there are exception ,most sensor 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 sensor. Similar combination can be made for other energy input such as thermal. Photo, magnetic and chemical,giving thermoelectric, photoelectric,electromaanetic, and electrochemical sensor respectively.

2 Sensor Sensitivity

The relationship between the measured and the sensor output signal is usually obtained by calibration tests and is referred to as the sensor sensitivity K1= output-signal increment / measured increment . In practice, the sensor 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 Sensor

The high sensor should exhibit the following characteristics.

(a)high fidelity-the sensor 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 sensor should not alter the measured in any way.

(c)Size. The sensor must be capable of being placed exactly where it is needed.

(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,for example,are often subjected to external effects such vibration and temperature.

(f)The natural frequency of the sensor should be well separated from the frequency and harmonics of the measurand.

Sensors can be divided into the following categories：

1 Electrical Sensor

Electrical sensor exhibit many of the ideal characteristics. In addition they offer high sensitivity as well as promoting the possible of remote indication or mesdurement.

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 types

These 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 types

These 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 Sensor

Resistance 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-circuit methods. Examples of this group include strain gauges and resistance thermometers.

3 Capacitive Sensor

The 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 sensor has an infinite resolution making it most suitable for

measuring small increments of displacement or quantities which may be changed to produce a displacement.

4 Inductive Sensor

The inductance can thus be made to vary by changing the reluctance of 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 possible

Typical measurands are displacement, pressure, vibration, sound, and liquid level.

5 Linear Variable-differential Ttransformer

6 Piezo-electric Sensor

7 Electromagnetic Sensor

8 Thermoelectric Sensor

9 Photoelectric Cells

10 Mechanical Sensor and Sensing Elements

In 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 after having been developed Modern computer technology and communication, not only requests sensor precision reliability, speed of response and gain information content request more and more high but also requests its cost to be inexpensive. The obvious traditional 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 obtained the 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. Japanese Sharp 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. Its manufacture 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 wi th this kind of immune body may to some organism in whether has this kind of ant original work inspection. Like may 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 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; 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 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 survey scope 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 transmission light wave intensity, the phase, the frequency, change and 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, magnetic field 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, the path 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 development. Will integrate the path of ray’s component to re place the original 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’ corrosion technology 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 the feeling 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 the frequency 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 the electrical 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 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 sensitive is small surveyed, may make the blood pressure pressure transmitter.

The Chinese aviation main corporation Beijing observation and control 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 senso r which American LUCAS, NOVASENSOR Corporation 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.

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-3000 intelligence sensor, the 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 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 senso r is extremely important. Our country in this 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 especia lly the 80'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.

——From《Sensor Technology Handbook》,Jon Wilson,Newnes

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。输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。如果把计算机比作大脑，那么

传感器则相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。自动化程度越高，系统对传感器要求越高。

传感器的几个关键词：

1传感器元件

除特例外，大多数的传感器都由敏感元件、转换元件或控制元件组成。如振动膜、波纹管、应力管和应力环、低音管和悬臂都是敏感元件，它们对压力和力作出响应把物理量转变成位移。然后位移可以改变电参数，如电压、电阻、电容或者感应系数。机械式和电子式元件合并形成机电式传感设备或传感器。这样的组合可用来输入能量信号。热的，光的，磁的和化学的相互结合产生的热电式、光电式、电磁式和电化学式传感器。

2 传感器灵敏度

通过校正测量系统获得的被测物理量和传感器输出信号的关系叫做传感器灵敏度K1，也就是K1=输出信号增量/测量增量。实际中，传感器的灵敏度是已知的，并且通过测量输出信号，输入量由下式决定，输入量=输出信号增量/K1。

3 理想传感器的特性

（a）高保真性：传感器输出波形应该真实可靠地再现被测量，并且失真很小。

（b）可测量最小的干扰，任何时候传感器的出现不能改变被测量。

（c）尺寸：传感器必须能正确地放在所需的地方。

（d）被测量和传感器信号之间应该有一个线性关系。

（e）传感器对外部影响的灵敏度应该小，例如压力传感器经常受到外部振动和温度的影响。

（f）传感器的固有频率应该避开被测量的频率和谐波。

传感器可分为以下几类：

1 电传感器

电传感器具有许多理想特性。它们不仅实现远程测量和显示，还能提供高灵敏度。

电传感器可分为两大类。

（a）变参数型，包括：

（i）电阻式；

（ii)电容式；

（iii)自感应式；

（v)互感应式；

这些传感器的工作依靠外部电压。

（b）自激型，包括：

（i）电磁式；

（ii）热电式；

（iii）光栅式；

（iv）压电式。

这些传感器根据测量输入值产生输出电压，而且这一过程是可逆的。比如，在一般情况下，压电式传感器可根据晶体材料的变形产生一个输出电压；但是，如果在材料上施加一个可变电压，传感器可以通过变形或与变电压同频率的振动来体现可逆效应。

2 电阻式传感器

电阻式传感器可以分为两大类：

（i)那些表现为大电阻变化的物理量可通过分压方式进行测量，电位器就属于此类。（ii）那些表现为小电阻变化的物理量可通过桥电路方式进行测量，这一类包括应变仪和电阻温度计。

3 电容式传感器

电容量随着相对介电常数、截面面积、或者极板间的距离的变化而变化。电容的特征曲线表明，在空间的一段范围内，截面面积和相对介电常数的变化与电容量变化成线性关系。不象电位器，变极距型电容传感器有无限的分辨率，这最适合测量微小的位移增量的位移。

4 电感式传感器

电感可以通过改变电感电路的阻抗来调节。

电容式和电感式传感器的测量技术：

（a）用差分式电容或电感作为交流电桥；

（b）用交流电位计电路做动态测量；

（c）用直流电路为电容器提供正比于容值变化的电压；

（d）采用调频法，C或者L随着振荡电路频率的变化而改变。

电容式和电感式传感器的一些重要特性如下：

（i)分辨率无限

（ii）精确到满量程的±0.1%

（iii）位移范围从25*10-6m到10-3m

（iv）上升时间小于50us

典型的被测量是位移、压力、振动量、声音和液位。

5 线性调压器

6 压电式传感器

7 电磁式传感器

8 热电式传感器

9 光电管

10 机械式传感器及敏感元件

在今天的信息时代里，信息产业包括信息采集、传输、处理三部分，即传感技术、通信技术、计算机技术。现代的计算机技术和通信技术由于超大规模集成电路的飞速发

展，而已经充分发达后，不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高，还要求其成本低廉且使用方便。显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。世界许多发达国家都在加快对传感器新技术的研究与开发，并且都已取得极大的突破。如今传感器新技术的发展，主要有以下几个方面：利用物理现象、化学反应、生物效应作为传感器原理，所以研究发现新现象与新效应是传感器技术发展的重要工作，是研究开发新型传感器的基础。日本夏普公司利用超导技术研制成功高温超导磁性传感器，是传感器技术的重大突破，其灵敏度高，仅次于超导量子干涉器件。它的制造工艺远比超导量子干涉器件简单。可用于磁成像技术，有广泛推广价值。

利用抗体和抗原在电极表面上相遇复合时，会引起电极电位的变化，利用这一现象可制出免疫传感器。用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。如用肝炎病毒抗体可检查某人是否患有肝炎，起到快速、准确作用。美国加州大学巳研制出这类传感器。

传感器材料是传感器技术的重要基础，由于材料科学进步，人们可制造出各种新型传感器。例如用高分子聚合物薄膜制成温度传感器；光导纤维能制成压力、流量、温度、位移等多种传感器；用陶瓷制成压力传感器。高分子聚合物能随周围环境的相对湿度大小成比例地吸附和释放水分子。高分子电介常数小，水分子能提高聚合物的介电常数。将高分子电介质做成电容器，测定电容容量的变化，即可得出相对湿度。利用这个原理制成等离子聚合法聚苯乙烯薄膜温度传感器，其有以下特点：测湿范围宽；温度范围宽，可达-400℃～+1500℃；响应速度快，小于1S；尺寸小，可用于小空间测试；温度系数小。

陶瓷电容式压力传感器是一种无中介液的干式压力传感器。采用先进的陶瓷技术和厚膜电子技术，其技术性能稳定，年漂移量小于0.1%F.S,温漂小于±0.15%/10K,抗过载强,可达量程的数百倍。测量范围可从0到60Mpa。德国E+H公司和美国Kahlo公司产品处于领先地位。

光导纤维的应用是传感材料的重大突破，其最早用于光通信技术。在光通信利用中发现当温度、压力、电场、磁场等环境条件变化时，引起光纤传输的光波强度、相位、频率、偏振态等变化，测量光波量的变化，就可知道导致这些光波量变化的温度、压力、电场、磁场等物理量的大小，利用这些原理可研制出光导纤维传感器。光纤传感器与传统传感器相比有许多特点：灵敏度高，结构简单、体积小、耐腐蚀、电绝缘性好、光路可弯曲、便于实现遥测等。光纤传感器日本处于先进水平。如IdecIzumi公司和Suns公司。光纤传感受器与集成光路技术相结合，加速光纤传感器技术的发展。将集成光路器件代替原有光学元件和无源光器件，使光纤传感器有高的带宽、低的信号处理电压，可靠性高，成本低。

半导体技术中的加工方法有氧化、光刻、扩散、沉积、平面电子工艺，各向导性腐蚀及蒸镀，溅射薄膜等，这些都已引进到传感器制造。因而产生了各种新型传感器，如利用

半导体技术制造出硅微传感器，利用薄膜工艺制造出快速响应的气敏、湿敏传感器，利用溅射薄膜工艺制压力传感器等。

日本横河公司利用各向导性腐蚀技术进行高精度三维加工，制成全硅谐振式压力传感器。核心部分由感压硅膜片和硅膜片上面制作的两个谐振梁结成，两个谐振梁的频差对应不同的压力，用频率差的方法测压力，可消除环境温度等因素带来的误差。当环境温度变化时，两个谐振梁频率和幅度变化相同，将两个频率差后，其相同变化量就能够相互抵消。其测量最高精度可达0.01%FS。

美国Silicon Microstructure Inc(SMI)公司开发一系列低价位,线性度在0.1%到0.65%范围内的硅微压力传感器,最低满量程为0.15psi(1KPa),其以硅为材料制成,具有独特的三维结构,轻细微机械加工,和多次蚀刻制成惠斯登电桥于硅膜片上,当硅片上方受力时,其产生变形,电阻产生压阻效应而失去电桥平衡,输出与压力成比例的电信号。象这样的硅微传感器是当今传感器发展的前沿技术,其基本特点是敏感元件体积为微米量级,是传统传感器的几十、几百分之一。在工业控制、航空航天领域、生物医学等方面有重要的作用，如飞机上利用可减轻飞机重量，减少能源。另一特点是能敏感微小被测量，可制成血压压力传感器。

中国航空总公司北京测控技术研究所，研制的CYJ系列溅谢膜压力传感器是采用离子溅射工艺加工成金属应变计，它克服了非金属式应变计易受温度影响的不足，具有高稳定性，适用于各种场合，被测介质范围宽，还克服了传统粘贴式带来的精度低、迟滞大、蠕变等缺点，具有精度高、可靠性高、体积小的特点，广泛用于航空、石油、化工、医疗等领域。

集成传感器的优势是传统传感器无法达到的，它不仅仅是一个简单的传感器，其将辅助电路中的元件与传感元件同时集成在一块芯片上，使之具有校准、补偿、自诊断和网络通信的功能，它可降低成本、增加产量，美国LUCAS、NOV ASENSOR公司开发的这种血压传感器，每星期能生产1万只。

智能化传感器是一种带微处理器的传感器，是微型计算机和传感器相结合的成果，它兼有检测、判断和信息处理功能，与传统传感器相比有很多特点：

具有判断和信息处理功能，能对测量值进行修正、误差补偿，因而提高测量精度；

可实现多传感器多参数测量；

有自诊断和自校准功能，提高可靠性；

测量数据可存取，使用方便；

有数据通信接口，能与微型计算机直接通信。

把传感器、信号调节电路、单片机集成在一芯片上形成超大规模集成化的高级智能传感器。美国HONYWELL公司ST-3000型智能传感器，芯片尺寸才有3×4×2mm3，采用半导体工艺，在同一芯片上制成CPU、EPROM、静压、压差、温度等三种敏感元件。

智能化传感器的研究与开发，美国处于领先地位。美国宇航局在开发宇宙飞船时称

这种传感器为灵巧传感器（Smart?Sensor），在宇宙飞船上这种传感器是非常重要的。我国在这方面的研究与开发还很落后，主要是因为我国半导体集成电路工艺水平有限。

传感器的发展日新月异，特别是80年代人类由高度工业化进入信息时代以来，传感器技术向更新、更高的技术发展。美国、日本等发达国家的传感器技术发展最快，我国由于基础薄弱，传感器技术与这些发达国家相比有较大的差距。因此，我们应该加大对传感器技术研究、开发的投入，使我国传感器技术与外国差距缩短，促进我国仪器仪表工业和自化化技术的发展。

摘自——《传感器技术手册》,Jon Wilson，Newnes