The thermoelectrode material of the thermocouple temperature sensor refers to the material that has good thermoelectric characteristics and physical and chemical properties, and is matched according to certain requirements to make the positive and negative thermoelectrodes of the thermocouple. The shapes of the thermoelectrode materials of common thermocouple sensors include rods, wires, sheets, membranes, etc., but the thermoelectrode materials of most thermocouple temperature sensors are filamentous.
From the perspective of application, the thermoelectrode materials of thermocouple sensors can be divided into two categories: standard thermoelectrode materials and non-standard thermoelectrode materials. Standard thermoelectrode materials refer to thermoelectrode materials that have been mass-produced and used, have stable manufacturing processes, and their performance meets national standards, and also have a unified indexing table; non-standard thermoelectrode materials refer to those that have not been mass-produced and used, and the production process is still It is not stable and does not have the thermoelectrode material to develop a unified indexing table.
In theory, although any two kinds of conductor (or semiconductor) materials can be used to prepare thermocouples, as a practical temperature measuring element, the thermocouple sensor material must meet the following requirements:
(1) The thermoelectromotive force of the material of the thermocouple sensor should be large enough, and change with the temperature as a single value function, that is, the E-T characteristic is linear, so that the thermocouple made has a large enough thermoelectromotive force. In addition, the rate of change of the thermoelectromotive force with temperature (Seebeck coefficient) should be large to ensure the high sensitivity of the thermocouple. To
(2) The thermoelectrode material of the thermocouple sensor has good chemical properties, and has good resistance to oxidation and corrosion of environmental media within the measurement temperature range, so that the thermocouple sensor can work normally in it.
(3) The thermal electrode material has good physical properties, does not produce obvious grain growth or evaporation within the specified temperature range, and the characteristics of the thermocouple sensor do not change with time.
(4) The melting point of the thermoelectrode material should be high enough so that the thermocouple sensor can work in a wide temperature range. Usually the high temperature of thermocouple is 50°C~150°C lower than its melting point.
(5) The thermoelectric characteristics of the thermoelectrode material should have good reproducibility, as well as processability and interchangeability in order to formulate a unified indexing table. To
(6) The thermoelectrode material of the thermocouple sensor should have high conductivity, low temperature coefficient of resistance and low thermal conductivity. For thermocouples used in atomic reactors, it is also desirable that the materials have a low neutron capture cross-sectional area.
(7) The thermoelectrode material should have good plasticity and appropriate mechanical strength to facilitate the drawing of the double wire.
The protection tube of the thermocouple sensorr is an important part of the thermocouple thermometer. It is used to protect the temperature sensing element of the thermocouple temperature sensor from chemical corrosion and mechanical damage of the measured medium. Therefore, it must have the characteristics of high temperature resistance, corrosion resistance, good air tightness and good thermal conductivity. It also requires sufficient mechanical strength and a certain ability to withstand sudden changes in temperature. Therefore, it plays an important role in both use and installation.
The above is an introduction to the characteristics of the thermoelectrode material of the thermocouple temperature sensor. With the development of technology, the application of common thermocouple sensors is very extensive. If you have more questions about the thermocouple temperature sensor, please contact Guangzhou Hui Yuan Mechanical & Electrical Co., Ltd.!