What is the difference between armored thermocouple and multi-point armored thermocouple?

The thermoelectric potential of the armored thermocouple will increase as the temperature of the measuring end increases. The size of the thermoelectric potential is only related to the material of the thermocouple conductor and the temperature difference between the two ends, and has nothing to do with the length and diameter of the thermoelectrode.

The two ends of the conductors of two different components are welded to form a loop. The direct temperature measuring end is called the working end, and the 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 loop. When the display instrument is connected, the corresponding temperature value of the thermoelectric potential generated by the thermocouple will be indicated on the instrument.

The multi-point armored thermocouple is a new generation of series products carefully designed and manufactured by Chongqing Oude Instrument Co., Ltd. and complies with the standards of the International Electrotechnical Commission (IEC). It is a special sensor specially designed for the chemical industry (fertilizer industry synthesis tower, reaction tank), metallurgy, petrochemical, and gas industries. When using this multi-point armored thermocouple, the user needs to prepare an external protective tube, otherwise it can only measure normal pressure and non-corrosive media.

The structural principle of armored thermocouple

It is made of conductor, high insulation magnesium oxide, outer jacket 1Cr18Ni9Ti stainless steel protection tube, and is drawn in one piece many times. The armored thermocouple product is mainly composed of junction box, terminal block and armored thermocouple, and is equipped with various installation and fixing devices. What is the difference between armored thermocouple and multi-point armored thermocouple

Armored thermocouple is divided into two types: insulated type and shell type.

It has many advantages such as bending, high pressure resistance, fast thermal response time and durability. It is the same as industrial use. As a sensor for measuring temperature, it is usually used with display instruments, recording instruments and electronic regulators. At the same time, it can also be used as a temperature sensing element. It can directly measure the temperature of liquid, steam and its gas medium and solid surface in the range of 0℃~800℃ in various production processes. Compared with, armored thermocouple has the advantages of bendability, high pressure resistance, short thermal response time and durability.

Thermocouple temperature measurement principle

is based on thermoelectric effect. When two different conductors or semiconductors are connected 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.

As a temperature measurement sensor, armored thermocouples are usually used in conjunction with temperature transmitters, regulators and display instruments to form a process control system to directly measure or control the temperature of fluids, steam and gas media and solid surfaces in the range of 0-1800℃ in various production processes.

Armored thermocouples have many advantages such as bendability, high pressure resistance, fast thermal response time and durability. Like industrial assembled thermocouples, they are used as temperature measurement sensors through compensation wires and display meters, recording instruments and electronic regulators.

Calibration method of armored thermocouples

Calibration method and device for metal melt fast armored thermocouples.

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

Verification method:

First, use two calibration thermocouples to find the point in the flat heating coil that makes the thermoelectric potential of the two calibration thermocouples the same, replace one of the calibration thermocouples with the tested thermocouple, and when other conditions remain unchanged, wait for the reading of the tested thermocouple to stabilize and compare it with the reading of the calibration thermocouple to know whether the value of the tested thermocouple is accurate.

Features:

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

b. The verification method is to first insert the two calibration thermocouples from both ends of the heating coil relative to each other so that the hot ends of the armored thermocouples are in contact, and change the position of the calibration thermocouple in the heating coil to make the thermoelectric potential of the two calibration thermocouples the same, replace one of the calibration thermocouples with the tested fast thermocouple, read its thermoelectric potential value in a stable state and compare it with the thermoelectric potential of the calibration thermocouple to know the accuracy of the tested fast armored thermocouple.