Thermocouple is a common temperature measurement element commonly used in the temperature measurement instrument. It directly measures the temperature and converts the temperature signal to the thermal electromotive force signal, and the electrical instrument (secondary instrument) is converted to the temperature of the measuring medium.The appearance of various thermocouples is often very different because of the need, but their basic structure is roughly the same. It is usually composed of the main parts such as thermocointed, insulating cases and wiring boxes. It usually shows the instrument, record instrument and electronic adjustmentUse.
K -type hot electric puppet
I. Overview of the K -type thermocouple as a temperature sensor. The K -type thermocouple is usually used to display the instrument, recording instruments and electronic regulators.The K -type thermocouple can directly measure the liquid steam and gas medium and the surface temperature of solids from 0 ℃ to 1300 ℃.The K -type thermocouple is usually composed of main components such as temperature sensing components, installing fixed devices and wiring boxes.The K -type thermocouple is currently the most consolidated hot -metal thermocouple, and its dosage is the sum of other thermocouple puppets.The diameter of the K -type thermal puppet is generally 1.2 to 4.0mm.The nominal chemical composition of the positive pole (KP) is: ni: CR = 90: 10, and the nominal chemical composition of the negative electrode (KN) is: ni: si = 97: 3, and its use temperature is -200 ~ 1300 ° C.The K -type thermocouple has the advantages of good linearity, large thermal electromotive motivation, high sensitivity, good stability and uniformity, strong antioxidant performance, cheap price, etc. It can be used in the use of users in oxidative inertia atmosphere.
The difference between thermal resistance and thermocouple
Both thermocouple and thermal resistance belong to the contact temperature measurement in temperature measurement. Although their effects are the same as measuring the temperature of the object, their principles and characteristics are different.The thermocouple is the most widely used temperature device in temperature measurement. His main feature is that the measurement range is wide, the performance is relatively stable, the structure is simple, the dynamic response is good, and the 4-20mA electrical signal can be passed away.EssenceThe temperature measurement principle of the thermocouple is based on the thermoelectric effect.Connect two different conductors or semiconductors into closed circuits. When the temperature at the two contacts is not at the same time, thermal power is generated in the circuit. This phenomenon is called thermoelectric effect, also known as the Syberg effect.There are two types of thermal potential generated in the closed loop: temperature difference potential and contact potential.
Thermocouple price
If it is a fast thermocouple, KSKB is generally about 4--5 yuan, about 2 yuan in KW.The one -meter -long ordinary K -type thermocouple 130 is about 80 yuan. If it is about 200 yuan with riot, it will be about 200 yuan.One meter -long wear -resistant thermocouple, about 400 yuan with a wear -resistant head of 300.The one-meter-long platinum hot electric puppet is currently around 2000--2500 yuan.
Thermocouple model
Commonly used thermocouples can be divided into two categories: standard thermocouple and non -standard thermocouple.The calling standard thermocouple refers to the thermocuel puppet that stipulates the relationship between its thermal power and temperature, allows errors, and has a unified standard score table. It has a supporting display instrument to choose from.Non -standardized thermocouples are not as good as standardized thermocouples in terms of range or quantity, and generally do not have a unified division table, which are mainly used for measurement in certain special occasions.Standardized thermocouple my country from January 1, 1988, all thermocouples and thermal resistance are produced according to IEC international standards, and seven standardized thermal puppets are specified in S, B, E, K, R, J, and T for the unified design type of China for the unified design of our country. Thermocouple.There are several types of thermocouples including S, R, B, N, K, E, J, and T.Among them, S, R, and B are precious metal thermos.The following is an explanation of the thermocouple dialogue number S platinum 10 pure platinum R 铑 13 pure platinum Bladder 30 platinum 6K nickel chromium nickel silicon T pure copper nickel, nickel, nickel chromium, silicon, silicon silicon e nickel e nickel e nickel eChromium copper nickel
Thermal electric puppet work principle
The basic principle of thermocouple temperature measurement is that two different ingredients of material conductors form a closed circuit. When there is a temperature gradient at both ends, the current will pass in the circuit. At this timeIt is the so -called Seebeckeffect.The homogeneous conductor of the two different ingredients is a thermal electrode, and one end with a higher temperature is the working end. The lower end of the temperature is the free end. The free end is usually at a constant temperature.According to the function of thermomotive force and temperature, the thermocouple division table is made; the separation table is obtained by the free end temperature when the temperature is 0 ° C. Different thermocouples have different score tables.

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