传感器中英文介绍

. sensors
sensors(English name: transducer/sensor) is a kind of detection device, can feel the measured information, and will feel information transformation according to certain rule become electrical signal output, or other form of information needed to satisfy the information transmission, processing, storage, display, record and control requirements.
Sensor's features include: miniaturization, digital, intelligent, multi-functional, systematic and network. It is the first step of automatic detection and automatic control. The existence and development of the sensor, let objects have sensory, such as touch, taste and smell let objects become live up slowly. Usually according to its basic cognitive functions are divided into temperature sensor, light sensor, gas sensor, force sensor, magnetic sensor, moisture sensor, acoustic sensor, radiation sensitive element, color sensor and sensor etc. 10 major categories.
temperature transducer
Temperature sensors (temperature transducer) refers to can feel temperature translates into usable output signal of the sensor. The temperature sensor is the core part of the temperature measuring instrument, wide variety. According to measuring methods could be divided into two types: contact and non-contact, according to the sensor material and electronic
component features divided into two categories, thermal resistance and thermocouple.
1 principle of thermocouple
Thermocouple is composed of two different materials of metal wire, the welded together at the end. To measure the heating part of the environment temperature, can accurately know the temperature of the hot spots. Because it must have two different material of the conductor, so called the thermocouple. Different material to make the thermocouple used in different temperature range, their sensitivity is also each are not identical. The sensitivity of thermocouple refers to add 1 ℃ hot spot temperature changes, the output variation of potential difference. For most of the metal material support thermocouple, this value about between 5 ~ 40 microvolt / ℃.
As a result of the thermocouple temperature sensor sensitivity has nothing to do with the thickness of material, use very fine material also can make the temperature sensor. Also due to the production of thermocouple metal materials have good ductility, the slight temperature measuring element has high response speed, can measure the process of rapid change.
Its advantages are:
(1)high precision measurement. Because of thermocouple direct contact with the object being measured, not affected by intermediate medium.
(2)the measurement range. Commonly used thermocouple from 1600 ℃to 50 ℃~ + sustainable measurement, some special thermocouple minimum measurable to - 269 ℃(e.g., gold iron nickel chrome), the highest measurable to + 2800 ℃ (such as tungsten rhenium).
(3) simple structure, easy to use. Thermocouple is usually composed of two different kinds of metal wire, but is not limited by the size and the beginning of, outside has protective casing, so very convenient to use. The thermocouple type and structure of the form.
2. The thermocouple type and structure formation
(1)the types of thermocouple
The commonly used thermocouple could be divided into two types: standard thermocouple and non-standard thermocouple. Standard thermocouple refers to the national standard specifies its thermoelectric potential and the relationship between temperature, permissible error, and a unified standard score table of thermocouple, it has with matching display instrument to choose from. Rather than a standard thermocouple or on the order of magnitude less than the range to use standardized thermocouple, in general, there is no uniform standard, it is mainly used for measurement of some special occasions.
Standardized thermocouple is our country from January 1, 1988, thermocouple and thermal resistance of all production according to IEC international standard, and specify the S, B, E, K, R,
J, T seven standardization thermocouple type thermocouple for our country unified design.
(2)to ensure that the thermocouple is reliable, steady work, the structure of thermocouple requirements are as follows:
①of the two thermocouple thermal electrode welding must be strong;
②two hot electrode should be well insulated between each other, in case of short circuit;
③compensation wires connected to the free cod of a thermocouple to convenient and reliable;
④protect casing thermal electrodes should be able to make sufficient isolation and harmful medium.
3.The thermocouple cold end temperature compensation
Due to the thermocouple materials are generally more expensive (especially when using precious metals), and the temperature measurement points are generally more far, the distance to the instrument in order to save materials, reduce cost, usually adopt the compensating conductor) (the free end of the cold junction of the thermocouple to the steady control of indoor temperature, connected to the meter terminals. It must be pointed out that the role of the thermocouple compensation wire extension hot electrode, so that only moved to the control room of the cold junction of the thermocouple instrument on the terminal, it itself does not eliminate the cold end temperature change on the influence of temperature, cannot have the compensation effect. So, still need to take some of the other correction method to compensate of the cold end temperature especially when t0 indicates influence on measuring temperature 0 ℃.
Must pay attention to when using thermocouple compensating conductor model match, cannot be wrong polarity, compensation conductor should be connected to the thermocouple temperature should not exceed 100 ℃.
传感器
传感器（名称：transducer/sensor）是一种检测装置，能感受到被测量的信息，并能将感受到的信息，按一定规律变换成为电信号或其他所需形式的信息输出，以满足信息的传输、处理、存储、显示、记录和控制等要求。

传感器的特点包括：微型化、数字化、智能化、多功能化、系统化、网络化。

它是实现自动检测和自动控制的首要环节。

传感器的存在和发展，让物体有了触觉、味觉和嗅觉等感官，让物体慢慢变得活了起来。

通常根据其基本感知功能分为热敏元件、光敏元件、气敏元件、力敏元件、磁敏元件、湿敏元件、声敏元件、放射线敏感元件、色敏元件和味敏元件等十大类。

温度传感器：
温度传感器（temperature transducer）是指能感受温度并转换成可用输出信号的传感器。

温度是的核心部分，品种繁多。

按测量方式可分为接触式和非接触式两大类，按照及电子元件特性分为热电阻和两类。

1、热电偶原理
热电偶由两个不同材料的金属线组成，在末端焊接在一起。

再测出不加热部位的环境温度，就可以准确知道加热点的温度。

由于它必须有两种不同材质的导体，所以称之为热电偶。

不同材质做出的热电偶使用于不同的温度范围，它们的灵敏度也各不相同。

热电偶的灵敏度是指加热点温度变化1℃时，输出电位差的变化量。

对于大多数金属材料支撑的热电偶而言，这个数值大约在5～40微伏/℃之间。

由于热电偶温度传感器的灵敏度与材料的粗细无关，用非常细的材料也能够做成温度传感器。

也由于制作热电偶的金属材料具有很好的延展性，这种细微的测温元件有极高的响应速度，可以测量快速变化的过程。

它的优点是：
（1）测量精度高。

因热电偶直接与被测对象接触，不受中间介质的影响。

（2）测量范围广。

常用的热电偶从-50℃~+1600℃可持续测量，某些特殊热电偶最低可测到-269℃（如金铁镍铬），最高可测到+2800℃（如钨-铼）。

（3）构造简单，使用方便。

热电偶通常是由两种不同的金属丝组成，而且不受大小和开头的限制，外有保护套管，所以用起来非常方便。

2、热电偶的种类及结构形成
（1）热电偶的种类
常用的热电偶可分为标准热电偶和非标准热电偶两大类。

所谓标准热电偶是指国家标准规定了其热电势与温度的关系、允许误差、并有统一的标准分度表的热电偶，它有与其配套的显示仪表可供选用。

而非标准化热电偶在使用范围或数量级上均不及标准化热电偶，一般也没有统一的标准，它主要用于某些特殊场合的测量。

标准化热电偶是我国从1988 年1 月 1 日起，热电偶和热电阻的生产全部按IEC 国际标准进行，并指定S、B、E、K、R、J、T 七种标准化热电偶为我国统一设计型热电偶。

（2）为了保证热电偶可靠、稳定地工作，对热电偶的结构要求如下：
①组成热电偶的两个热电极的焊接必须牢固；
②两个热电极彼此之间应能很好地绝缘，以防短路；
③补偿导线与热电偶自由端的连接要方便、可靠；
④保护套管应能保证热电极与有害介质充分隔离。

3、热电偶冷端的温度补偿
由于热电偶的材料一般都比较贵重（特别是采用贵金属时），而测温点到仪表的距离一般都比较远，为了节省材料，降低成本，通常采用补偿导线把热电偶的冷端（自由端）延伸到温度比较稳定的控制室内，连接到仪表端子上。

必须指出的是，热电偶补偿导线的作用只起延伸热电极、使热电偶的冷端移动到控制室的仪表端子上的作用，它本身并不能消除冷端温度变化对测温的影响，不能起到补偿作用。

因此，还需采用其它修正方法来补偿冷端温度特别是当t0≠0℃时对测温的影响。

在使用热电偶补偿导线时必须注意型号相配，极性不能接错，补偿导线与热电偶连接
端的温度不能超过100℃。