温度传感器概述Word格式文档下载.docx

1、thermocouple. Thermocouple made of different materials used in different temperature ranges,Their sensitivity is also different. The sensitivity of the thermocouple is hot temperature increases 1 , the output potential difference of the variation. For most metallic materials in terms of supporting t

2、he thermocouple, the value of about 5 to 40 micro V / between.Thermocouple sensor has its own advantages and disadvantages, it is relatively low sensitivity, susceptible to the impact of environmental interference signal is also vulnerable to the impact of pre-amplifier temperature drift, therefore

3、not suitable for measuring small temperature changes. Since the sensitivity of the thermocouple temperature sensor has nothing to do with the material thickness, with very thin material made of the temperature sensor can. Because of the thermocouple also has good ductility of metal materials, such d

4、etailed temperature measurement device has high response speed, the process of rapid change can be measured.Temperature sensor is the most diverse variety of sensors commonly used in a modern form of temperature sensor is too small, so it is more widely used practice in all areas of production, but

5、also for our lives to provide the facilities and features numerous.There are four main types of temperature sensors: thermocouples, thermistors, resistance temperature detector （RTD） and IC temperature sensors. IC temperature sensor, it also includes analog outputs and digital output of two types.Co

6、ntact temperature sensor and measured object detection part of the good contact, also known as thermometer.Thermometer through conduction or convection thermal equilibrium, so that a direct indication of the thermometer that the temperature of the measured object. Generally higher measurement accura

7、cy. Within a certain temperature, the thermometer is also measurable temperature distribution within the object. But for sports, small objects or very small heat capacity, the object will have a greater measurement error, commonly used in thermometers are bimetal thermometers, glass liquid thermomet

8、er, pressure thermometer, resistance thermometer, thermistor, and thermocouple and so on. They are widely used in industry, agriculture, commerce and other departments. In daily life people often use the thermometer.Of low temperature technology in national defense engineering, space technology, met

9、allurgy, electronics, food, medicine and oil and chemical sector and the wider use of superconducting technology studies, measuring the temperature of 120K the following low-temperature thermometer have been developed, such as low temperature gas thermometer, steam pressure thermometer, acoustic the

10、rmometer, paramagnetic salt thermometer, quantum thermometers, low-temperature heat resistance and low temperature thermocouple and so on. Low-temperature thermometer required temperature sensing small size, high accuracy, reproducibility and stability. Porous high silica glass sintered carburizing

11、carburizing heat resistance of glass is a low-temperature thermometer temperature sensing devices can be used to measure the range of 1.6300K temperature.Non-contact temperature sensor sensitive components and the measured object does not touch each other, also known as non-contact Thermometer. This

12、 instrument can be used to measure moving objects, small target and heat capacity of small or rapid temperature changes （transient） object surface temperature can also be used to measure the temperature of the temperature distribution. The most common form of non-contact thermometer based on the bas

13、ic law of blackbody radiation, known as the Radiation Thermometer. Including the brightness of radiation temperature measurement method （see optical pyrometer）, radiation （see Radiation Pyrometer） and colorimetry （see colorimetric thermometer）.Various types of radiation thermometry method can only d

14、etect the corresponding brightness temperature, radiant temperature or the ratio of color temperature. Only on the black body （do not absorb all the radiation reflected light of the object） the measured temperature is the true temperature. For determination of the true temperature of the object, it

15、must be modified surface emissivity. The surface emissivity depends not only on temperature and wavelength, but also with the surface state, such as the coating and microstructure, it is difficult to accurately measure. In automated production often requires the use of radiation thermometry to measu

16、re or control the surface temperature of certain objects, such as the metallurgy of the steel rolling temperature, roll temperature, forgingTemperature and a variety of molten metal in the smelting furnace or crucible in the temperature. In these specific cases, the measurement of surface emissivity

17、 is very difficult. The solid surface temperature measurement and automatic control, can be used to make additional mirror surface to be measured together with the composition of the blackbody cavity. Additional radiation can increase the effective surface radiation measured and the effective emissi

18、on coefficient. Through the instrument using the effective emission coefficient corresponding to the measured temperature of the amendment, eventually get the real measured surface temperature. The most typical is the hemisphere mirror attached mirror. The surface of the ball near the center of diff

19、use radiation measured by the hemisphere mirrorReflected back to the surface of the formation of additional radiation, thereby enhancing the effective emission coefficient: the formula for the surface emissivity , for the mirror reflectivity. As for the real gas and liquid medium temperature radiati

20、on measurement, the tube can be inserted to a certain depth of heat-resistant material to form a black body cavity method. Calculated by calculating the thermal equilibrium with the media after the effective emission coefficient of cylindrical cavity. In the automatic measurement and control can use

21、 this value to the end of the test chamber temperature （medium temperature） to amend and get the real temperature of the medium.Advantages of non-contact temperature measurement: measuring temperature sensing temperature limit the extent not subject to the restrictions, and thus the maximum temperat

22、ure can be measured in principle, no limit. For temperatures above 1800 , mainly non-contact temperature measurement. With infrared technology, radiation temperature gradually extended from the visible to infrared, 700 ambient temperature until the following have been adopted, and high resolution.RT

23、D temperature sensor classification1. Conductor thermal resistancePlatinum resistance temperature sensorCopper resistance temperature sensorIndium resistance temperature sensorRh-Fe resistance temperature sensorCobalt platinum resistance temperature sensor2. Semiconductor thermal resistanceGermanium

24、 resistance temperature sensorCarbon resistor temperature sensorsCarbon glass resistor temperature sensorNTC thermistor temperature sensorSensor static characteristicsStatic characteristics of the sensor is on the static input signal, the sensor output and input between a relationship. Since then bo

25、th input and output, and time-independent, so the relationship between them, that the sensor can be a static characteristic of the algebraic equation without the time variable, or input for the horizontal, to its corresponding output for vertical axis and draw the characteristic curve. Characterizat

26、ion of the static sensors, the main parameters are: linearity, sensitivity, hysteresis, repeatability, drift, etc.（1） linearity: that sensor output and the input of the actual relationship between the degree curve deviated from the fitted line. Defined as the full scale range of the actual performan

27、ce curve with the maximum deviation between the fitted line and the full scale output value of the ratio.（2） Sensitivity: Sensitivity is the static characteristics of sensors is an important indicator. Defined as the incremental output and lead to the corresponding input of the incremental ratio of

28、increment. S said with sensitivity.（3） hysteresis: sensor input from small to large （positive stroke）, and input from big to small （anti-stroke） during changes in its input-output characteristic curve does not coincide with a hysteresis phenomenon. For the same size of the input signal, sensor output signal of the positive and negative travel size are not equal, this difference is called hysteresis margin.（4） Repeatability: Repeatability is the sensor in the input direction by the