Is Pt100 A Thermocouple Or A Thermal Resistor? Is Cu50 A Thermocouple Or A Thermal Resistor? What Is The Difference Between Each Other?

Is pt100 a thermocouple or a thermal resistor? Is cu50 a thermocouple or a thermal resistor? What is the difference between each other?

Pt100 : PT means platinum resistance, the latter 100 means that it has a resistance of 100 ohms at 0 ° C.

Pt100 is not a thermocouple, a large class is a thermal resistor

Cu50 is not a thermocouple, a large class is a thermal resistor

The common saying is that pt100 thermal resistance, cu50 thermal resistance

Thermocouples and thermal resistors are contact temperature measurement in temperature measurement. Although their functions are the same as measuring the temperature of objects, their principles and characteristics are not the same.

First, introduce the thermocouple. Thermocouple is the most widely used temperature device in temperature measurement. Its main features are wide temperature measurement range, stable performance, simple structure, good dynamic response, and better remote transmission of 4-20mA. Signal for easy automatic control and centralized control. The thermometry principle of thermocouples is based on the thermoelectric effect. Connecting two different conductors or semiconductors into a closed loop, when the temperatures at the two junctions are different, a thermoelectric potential will be generated in the loop. This phenomenon is called the thermoelectric effect, also known as the Seebeck effect. The thermoelectric potential generated in the closed loop consists of two potentials: the temperature difference potential and the contact potential. The thermoelectric potential refers to the potential generated by the temperature difference between the two ends of the same conductor. Different conductors have different electron densities, so the potentials they generate are different. The contact potential, as the name suggests, refers to the contact of two different conductors. Because of their different electron densities, they generate a certain amount of electron diffusion. When they reach a certain equilibrium, the potential of the contact potential depends on the material properties of the two different conductors and the temperature of their contact points.

At present, the internationally applied thermocouple has a standard specification. The international thermocouple is divided into eight different scales, namely B, R, S, K, N, E, J and T, which can measure the lowest temperature. Measured at 270 degrees Celsius, up to 1800 degrees Celsius, where B, R, S belong to the platinum series of thermocouples. Because platinum is a precious metal, they are also called precious metal thermocouples and the remaining few are called cheap metal thermoelectrics. I. There are two types of thermocouples, normal and armored. Ordinary thermocouples are generally composed of hot electrodes, insulating tubes, protective sleeves and junction boxes, while armored thermocouples are assembled by combining thermocouple wires, insulating materials and metal protective sleeves. Stretched into a solid combination. However, the electrical signal of the thermocouple requires a special wire for transmission. This wire is called a compensation wire. Different thermocouples require different compensation wires. Their main function is to connect with the thermocouple, so that the reference end of the thermocouple is far away from the power supply, so that the reference junction temperature is stable. The compensation wire is divided into two types: compensation type and extension type. The chemical composition of the extension wire is the same as that of the compensated thermocouple. However, in practice, the extension type wire is not made of the same material as the thermocouple, and is generally used and thermoelectric. Instead of wires with the same electron density. The connection of the compensation wire to the thermocouple is generally very clear. The positive terminal of the thermocouple is connected to the red line of the compensation wire, and the negative electrode is connected to the remaining color. Most of the materials for the compensation wires are made of copper-nickel alloy.

Secondly, we introduce the thermal resistance. Although the thermal resistance is widely used in industry, its temperature range is limited by his temperature range. The temperature measurement principle of the thermal resistance is based on the resistance value of the conductor or semiconductor. The characteristic that changes with the change of temperature. It has many advantages, and it can also transmit electrical signals remotely. It has high sensitivity, strong stability, interchangeability and accuracy, but it requires power supply excitation and cannot instantaneously measure temperature changes. Industrial thermal resistance is generally Pt100, Pt10, Cu50, Cu100, the range of temperature measurement of platinum thermal resistance is generally 200-800 degrees Celsius, copper thermal resistance is minus 40 to 140 degrees Celsius. Thermistor is the same type of distinction as the thermocouple, but it does not require a compensation wire and is cheaper than a hot spot.