Selection of Thermocouple and Vacuum Gauge in Vacuum Heat Treatment Furnace

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The structure of the thermocouple, the key component of the temperature in the vacuum heat treatment furnace (0~1300℃ heating interval), and the type, advantages and disadvantages of the thermocouple in the vacuum heat treatment furnace.

Vacuum heat treatment technology has outstanding advantages such as non-oxidation, non-decarburization, and good surface quality. The heat-treated workpieces have made great progress in wear resistance and corrosion resistance. Vacuum heat treatment technology has been widely used in the treatment of key parts of various equipment, and is a key heat treatment technology in military and civilian products.

Vacuum heat treatment technology has become the main symbol of the current advanced heat treatment production technology. In recent years, vacuum heat treatment technology has developed rapidly. Vacuum heat treatment furnace is a necessary condition for vacuum heat treatment. The two important indexes of vacuum heat treatment are vacuum and temperature.

How to choose the thermocouple in the vacuum heat treatment furnace?

Generally, the types of thermocouples used in domestic vacuum heat treatment furnaces are: PT100 platinum resistance, K-type thermocouple, N-type thermocouple and S-type thermocouple. The difference in foreign countries is that the thermocouples used in the high-temperature section are different, and the B-type thermocouple and the R-type thermocouple are newly added.

First, the high temperature section (1000~1300℃): In this temperature section, the vacuum heat treatment furnace generally chooses S-type thermocouples in China. The S-type thermocouples are used at high temperature and have better performance indicators. At the same time, the S-type thermocouple is also used in the past. International standard thermocouple.

Second, the middle temperature section (300~1000℃): In this temperature section, we generally choose K-type thermocouple or N-type thermocouple. The traditional selection standard in our country is the K-type thermocouple, because the K-type thermocouple can meet the needs of this temperature section of the vacuum heat treatment furnace in the temperature measurement area and various aspects.

Third, the low temperature section (0~300℃): In this temperature section, we generally choose PT100 platinum resistance. Although the performance of PT100 platinum resistance is general, but in the low temperature section, the performance of PT100 can basically be To meet the requirements of the equipment, the most important thing is the price advantage of PT100 platinum resistance.

Vacuum gauge selection

Vacuum gauges commonly used in vacuum heat treatment furnaces are: ionization vacuum gauges, thermocouple vacuum gauges, and compound vacuum gauges.

First, the ionization vacuum gauge. Mainly used to measure high vacuum.

Second, the thermocouple vacuum gauge is composed of sensitive components, thermocouple gauges and measuring instruments. The measuring instrument is composed of two parts: a millivolt meter for measuring the thermoelectric potential and a regulated power supply for the heating wire.

Third, the compound vacuum gauge. Generally, the measurement of low vacuum and high vacuum cannot be done with a vacuum gauge, but a composite vacuum gauge should be used, and the ionization and thermocouple composite vacuum gauge is more widely used. The compound vacuum gauge is equipped with a thermocouple gauge and an ionization gauge, which are connected to the vacuum system. The two gauges can be heated by the knob and used separately.

Editor: Frank Lee

Copyright: SIMUWU Vacuum Furnace