What is the difference between armored thermal resistance and industrial platinum copper thermal resistance temperature instruments?

The copper thermal resistor of the industrial platinum copper thermal resistor is an instrument that measures temperature based on the principle that the resistance of the metal changes with temperature. Copper thermal resistors are divided into assembled type (detachable) and armored type (non-detachable, with built-in platinum resistor) according to the structure of their protective tubes. Thermal resistors are designed and manufactured based on the basic principle that the resistance value of platinum wire changes with temperature. According to the resistance value R (℃) at 0℃, they are divided into 10 ohms (Pt10) and 100 ohms (Pt100), etc. The temperature measurement range is large and suitable for -200~850℃.

Although armored thermal resistors are widely used in industry, their application is limited to a certain extent due to their temperature measurement range. The temperature measurement principle of thermal resistors is based on the characteristic that the resistance value of conductors or semiconductors changes with temperature. It has many advantages, and can also transmit electrical signals remotely, with high sensitivity, strong stability, good interchangeability and accuracy, but it requires power excitation and cannot measure temperature changes instantaneously. Industrial thermal resistors generally use Pt100, Pt10, Cu50, Cu100. The temperature measurement range of platinum thermal resistors is generally minus 200-800℃, and that of copper thermal resistors is minus 40 to 140℃. Thermal resistors are classified into the same types as thermocouples, but they do not require compensation wires and are cheaper than thermocouples.

Ordinary thermal resistors

From the temperature measurement principle of thermal resistors, it can be seen that the change in the measured temperature is directly measured by the change in the resistance value of the thermal resistor. Therefore, the change in the resistance of various wires such as the lead wire of the thermal resistor body will affect the temperature measurement. What is the difference between armored thermal resistors and industrial platinum copper thermal resistors?

Armored thermal resistors are solid bodies composed of temperature sensing elements (resistance bodies), lead wires, insulating materials, and stainless steel casings. Their outer diameter is generally φ2-φ8mm, and the smallest can reach φ0.25mm. Compared with ordinary thermal resistors, it has the following advantages:

① Small size, no air gap inside, small measurement value due to thermal inertia;

② Good mechanical properties, vibration resistance, and impact resistance;

③ Can be bent and easy to install;

④ Long service life.

Armored thermal resistors are commonly used temperature measuring elements in temperature measuring instruments. When the two ends of two conductors of different components are connected into a loop, when the temperatures of the two junction thermocouples are different, a thermal current will be generated in the loop. If there is a temperature difference between the working end and the reference end of the thermocouple, the display instrument will indicate the temperature value corresponding to the thermoelectric potential generated by the thermocouple.

Armored thermal resistor couple is a temperature sensor. It has a smaller diameter than assembled thermocouples, is easy to bend, and has good shock resistance. It is suitable for installation in places where assembled thermocouples cannot be installed. The armored thermocouples produced by the company use imported thermal resistor temperature measuring elements. Therefore, it has the advantages of accuracy, sensitivity, fast thermal response time, stable quality, and long service life.