What are the application characteristics of armored thermocouples

Armored thermocouple is a widely used temperature device in temperature measurement, characterized by a wide temperature measurement range, stable performance, simple structure, good dynamic response, and easy automatic and centralized control.

There is a standard specification for thermocouples used internationally, which specifies that thermocouples are divided into eight different divisions: b, r, s, k, n, e, j, and t. The lower division can measure temperatures as low as 270 degrees Celsius, while the higher division can reach 1800 degrees Celsius. Among them, b, r, and s belong to the platinum series thermocouples, which are also known as precious metal thermocouples because platinum is a precious metal, while the remaining ones are called cheap metal thermocouples.

There are two types of thermocouple structures, ordinary type and armored type.

Ordinary thermocouples are generally composed of hot electrodes, insulation tubes, protective sleeves, and junction boxes, while armored thermocouples are a solid combination of thermocouple wires, insulation materials, and metal protective sleeves assembled and stretched. However, the electrical signal of a thermocouple requires a special type of wire for transmission, which we call a compensating wire. Different thermocouples require different compensation wires, which are mainly used to connect with the thermocouple and keep the reference end of the thermocouple away from the power supply, thereby stabilizing the temperature of the reference end. Compensation wires are 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 wire is not made of the same material as the thermocouple, and is generally replaced with a wire with the same electron density as the thermocouple.