More About The Type J Thermocouple

Type J thermocouple is made from two materials, usually are used metal alloys. This one is made from constantan and iron. It is used to measure the temperature. The commercial ones are inexpensive and they can measure a large range of temperatures. This model, unlike some others has a more restricted scale but it is more sensitive.

As the others, it has two wires, called legs: a positive one and a negative one. The positive wire is made from iron. The negative wire has in his composition approximately 45 percent nickel and 55 percent copper. The constantan is an alloy made from copper and nickel.

The constantan is nickel- copper alloy. It also is known that the copper is a material used as a conductor for heat and electricity. Because of the materials that compose it, this model its not very expensive and it also is easy to find on market. Due to the iron component, this model is more susceptible to rusting and oxidation.

Each leg has a different property. The one that is made up of iron is a magnetic one. Because of the iron presence, its color is white and is susceptible not only to rust but the oxidation in entirety, particularly at temperatures below 0. The second leg is manufactured from constantan has the red color, is negative and it has no magnetic property. Constantan is an alloy of nickel and copper.

If its protected by a compacted mineral insulation, the instrument can be used from 0 to 816 Celsius degrees. The temperature range is 538 Celsius degrees. Even if it usually is usable until 816 Celsius degrees, it still is not recommended to use it above 750 Celsius degrees, because an abrupt magnetic transformation will cause permanent calibration. It also is highly recommended to use these instruments in inert, oxidizing, vacuum and reducing atmospheres up to 750 Celsius degrees.

These instruments are mostly used in science, mostly in the electrical engineering, and in industry. It can resist at higher temperatures if is protected by a compacted mineral insulation. But you must avoid use it in a sulfurous atmosphere above 540 Celsius degrees.

There are two stiles: bare wire and ceramic insulated. For a longer life its recommended to use a tube that will protect it. Since the wire made from iron will oxidize rapidly at temperatures over 540 Celsius degrees. These instruments are widely used in all kinds of industries. Their wide range of measurements makes them extremely popular. All these instruments, used in various applications are easy to obtain.