What is the difference between armored thermocouples and miniature thermocouples

The thermoelectric potential of armored thermocouples will increase as the temperature at the measuring end rises. The magnitude of the thermoelectric potential is only related to the material of the thermocouple conductor and the temperature difference at both ends, and is independent of the length and diameter of the thermoelectric electrode.

Two conductors with different compositions are welded at both ends to form a circuit. The temperature measuring end is called the working end, and the wiring terminal end is called the cold end, also known as the reference end. When there is a temperature difference between the working end and the reference end, a thermal current will be generated in the circuit. When connected to a display instrument, the instrument will indicate the corresponding temperature value of the thermoelectric potential generated by the thermocouple.

Micro thermocouples are even smaller than armored thermocouples, with advantages such as bending ability, high voltage resistance, fast thermal response time, and durability. Like armored thermocouples and assembled thermocouples, micro thermocouples are commonly used as temperature sensors in conjunction with display instruments, recorders, and electronic regulators. At the same time, micro thermocouples can also serve as temperature sensing elements for assembled thermocouples.

The structural principle of armored thermocouple

It is made of a conductor, high insulation magnesium oxide, and a protective tube made of 1Cr18Ni9Ti stainless steel, which has been drawn multiple times as a whole. Armored thermocouple products are mainly composed of junction boxes, terminal blocks, and armored thermocouples, and are equipped with various installation and fixing devices.

Armored thermocouples are divided into two types: insulated and shell connected.

It has many advantages such as bending ability, high pressure resistance, fast thermal response time, and durability. Like industrial sensors, it is usually used in conjunction with display instruments, recording instruments, and electronic regulators to measure temperature. At the same time, it can also be used as a temperature sensing element. It can directly measure the temperature of liquids, vapors, gas media, and solid surfaces in the range of 0 ℃~800 ℃ during various production processes. Compared to others, armored thermocouples have advantages such as bendability, high voltage resistance, short thermal response time, and durability.

The temperature measurement principle of thermocouple

It is based on the thermoelectric effect. Connecting two different conductors or semiconductors into a closed circuit, when the temperatures at the two junctions are different, a thermoelectric potential will be generated in the circuit. This phenomenon is called thermoelectric effect, also known as Seebeck effect.

Armored thermocouples, as temperature measurement sensors, are usually used in conjunction with temperature transmitters, regulators, and display instruments to form process control systems. They are used to directly measure or control the temperature of fluids, vapors, gas media, and solid surfaces within the range of 0-1800 ℃ in various production processes.

Armored thermocouples have many advantages such as bending, high voltage resistance, fast thermal response time, and durability. Like industrial assembled thermocouples, they are commonly used as temperature sensors in conjunction with display instruments, recording instruments, and electronic regulators.

Verification method for armored thermocouples

Verification method and device for rapid armored thermocouple of metal melt.

The device mainly consists of a flat heating coil that can accommodate two quartz tubes at the ends of the tested couples, two armored thermocouples with the same shape as the tested couples, and corresponding temperature control display output devices.

Verification method:

Firstly, use two calibration thermocouples to identify the point in the flat heating coil where the two calibration thermocouples have the same thermoelectric potential. Replace one of the calibration thermocouples with the tested thermocouple. Under other constant conditions, compare the reading of the tested thermocouple with the reading of the calibration thermocouple to determine whether the measured value of the tested thermocouple is accurate.

The characteristics are:

a, The device consists of a flat heating coil, a pair of calibrated armored thermocouples, and a temperature control display output device.

b, The verification method is to first insert two calibration thermocouples into the heating coil from opposite ends, so that the armored thermocouple contacts the hot end. By changing the position of the calibration thermocouple in the heating coil, the thermoelectric potential of the two calibration thermocouples is made the same. Replace one of the calibration thermocouples with the tested fast thermocouple, and compare its steady-state thermoelectric potential value with the thermoelectric potential of the calibration thermocouple to determine the accuracy of the tested fast armored thermocouple.