Fe-CuNi Type J Constantan Thermocouple Extension Wire Valued for its Accuracy and Stability in Industrial Processes

Fe-CuNi (Type J) Constantan Thermocouple Extension Wire is a type of thermocouple known for its durability and affordability. Type J thermocouples consist of an iron (Fe) positive wire and a copper-nickel (CuNi), or Constantan, negative wire.They are suitable for a broad temperature range from -210°C to 760°C, making them versatile for various industrial and scientific applications.

Type J thermocouples have good resistance to oxidation, which is beneficial for long-term stability in high-temperature environments.They provide a relatively high EMF output, which contributes to their sensitivity and accuracy in temperature measurement.Commonly used in applications such as furnaces, kilns, and other high-temperature processes where a cost-effective and reliable temperature measurement is needed.The iron wire has a high melting point and good thermal conductivity, while the Constantan wire offers a stable reference for temperature changes.

Type J thermocouples typically have a standard tolerance of ±1°C or better, ensuring accurate temperature readings.They are often chosen for applications where the cost of more expensive thermocouple types, like Type K, is not justified.Type J thermocouples are a popular choice for their balance of performance and cost, particularly in applications where the temperature range and resistance to oxidation are critical factors.

color codes of thermocouple ( J type )

The operating temperature range of type J thermocouple is -210~1200℃ , but it is usually used in the temperature range 0~750℃ due to embrittlement of Iron.

Type J thermocouple has good resistance to oxidation and high EMF output against Platinum 67, with good temperature accuracy, sensitivity and stability. It is recommended for vacuum, oxidizing, reducing or inert atmospheres, but it can not be used in sulphurous atmosphere above 500℃ .

Thermocouple temperature range and tolerance

Some Key Features Fe-CuNi (Type J) Constantan Thermocouple Extension Wire include:

• Temperature Range: Type J thermocouples operate from -180°C to +700°C, with an extended range of -210°C to +1200°C, though typically used up to 750°C due to iron embrittlement at higher temperatures
• Chemical Composition: The positive leg (JP) is made of pure iron, while the negative leg (JN) is an alloy with approximately 55% copper and 45% nickel
• Resistance to Oxidation: Type J thermocouples exhibit good resistance to oxidation, maintaining accuracy and stability in various atmospheres including vacuum, oxidizing, reducing, or inert
• EMF Output: They have a high EMF output compared to Platinum 67, ensuring good temperature accuracy, sensitivity, and stability
• Physical Properties: The density of JP is 7.8 g/cm³ with a melting point of 1407°C, while JN has a density of 8.8 g/cm³ and a melting point of 1220°C
• Limitations: Not suitable for use in sulphurous atmospheres above 500°C due to rapid oxidation of iron

Type J thermocouples are a robust choice for temperature measurement in a variety of industrial and commercial applications where resistance to oxidation and accuracy are paramount.

Applications:

• Metal Processing: Type J thermocouples are used in furnaces and kilns for temperature monitoring in metal processing industries.
• HVAC Systems: They are utilized in heating, ventilation, and air conditioning systems for indoor climate management.
• Food Processing: Accurate temperature measurement is crucial in food processing, and Type J thermocouples are used in ovens, refrigerators, and autoclaves for this purpose.
• Laboratories: These thermocouples are part of experimental setups in laboratories for temperature control and measurement.
• Automotive Industry: Type J thermocouples are used for monitoring component temperatures within the automotive industry.
• Petrochemical Sector: They ensure process control in the petrochemical sector, monitoring turbine temperatures in power generation facilities.
• Plastics Industry: Type J thermocouples are used to control and measure processing temperatures of injection molds.
• High Temperature Control: They are used for high-temperature control in iron casting and other manufacturing processes.
• Heating and Cooling Applications: Type J thermocouples are used in gas burners for ovens and freezers for cooling.
• Engine Protection: They measure temperatures and surface temperatures for engine protection.

These applications highlight the versatility of Type J thermocouples in providing temperature measurements in a broad range of environments and conditions.