Fe-CuNi Type J Thermocouple Wire Suitable For Moderate-Temperature Industrial Environments

The Fe-CuNi Type J thermocouple is a widely used temperature measurement device composed of an Iron (Fe) positive leg and a Copper-Nickel (CuNi), or Constantan, negative leg. It operates effectively in the temperature range of -210°C to +760°C (-346°F to +1400°F), with an electromotive force (EMF) output of approximately 55 µV/°C.

Type J thermocouples perform well in both oxidizing and reducing environments but are prone to rusting due to the iron leg, limiting their use in high-humidity or moist conditions. They are commonly employed in industrial processes, furnaces, and heat treatment applications, particularly in reducing or vacuum environments where their stability shines.

While cost-effective and reliable for general-purpose temperature measurement, Type J thermocouples are unsuitable for prolonged use above 760°C due to rapid oxidation of the iron leg, reducing their lifespan in high-temperature applications.

color codes of thermocouple ( J type )

Thermocouple temperature range and tolerance

Key Features of Fe-CuNi (Type J) Constantan Thermocouple Wire:

1. Composition:

• Positive Leg: Iron (Fe)
• Negative Leg: Copper-Nickel (CuNi), also known as Constantan.

2. Temperature Range:

• Effective operation from -210°C to +760°C (-346°F to +1400°F).

3. Sensitivity:

• Produces a moderate EMF output of approximately 55 µV/°C.

4. Environmental Performance:

• Performs well in oxidizing and reducing atmospheres.
• Susceptible to rusting in moist or high-humidity environments due to the iron leg.

​Applications of Fe-CuNi (Type J) Constantan Thermocouple Wire:

1. Industrial Processes:

• Widely used in manufacturing, heat treatment, and furnace applications to monitor temperatures in environments up to 760°C.
• Commonly applied in metal processing (e.g., steel and aluminum production), heat treatment of metals, and casting operations.

2. Furnaces and Kilns:

• Used in high-temperature furnaces for accurate temperature monitoring in processes like annealing, quenching, and tempering.

3. Reducing Atmospheres:

• Ideal for environments with reducing atmospheres, such as in vacuum chambers, where they offer stable performance compared to other thermocouple types.

3. Cryogenics and Low-Temperature Measurement:

• Effective in cryogenic temperature applications, extending down to -210°C, useful for research and scientific purposes requiring temperature accuracy in low-temperature systems.

4. Food and Pharmaceutical Industries:

• Used for temperature control in processes like sterilization, drying, and baking where precise heat monitoring is critical.

5. Laboratory Use:

• Often utilized in research environments and laboratories for general-purpose temperature measurements.

6. Environmental Monitoring:

• Applied for temperature monitoring in outdoor or weather-related applications, where conditions are less predictable.
• Type J thermocouples are reliable, cost-effective, and versatile in moderate-temperature applications. However, they should be avoided in environments with high humidity or above 760°C due to the potential for oxidation.

Cost-Effectiveness:

• Economical and reliable for general-purpose temperature measurements.

Limitations:

• Not suitable for prolonged use above 760°C due to iron oxidation.

Company Overview:

Jiangyin Chengxin Alloy Material Co., Ltd has more than 20 years of experience as the lead.ing alloy wire manufacturer in China. We offer a wide range of services from fine wire drawing toresistance wire manufacturing. Since the beginning, our specialty has been the quality and preci.sion of our products. We have the tightest tolerances and deliver within a few days to a fewweeks. As a result, we have become the leading alloy wire supplier in the industry.

Senphus Subsidiaries:

• Jiangyin Chengxin Alloy Material Co., Ltd.
• Jiangyin Senphus Electrical Materials Co., Ltd.
• Jiangsu Xiangcheng Supply Chain Management Co., Ltd.

Jiangyin Chengxin Alloy Material Co., Ltd.: With nearly 20 years of experience, Jiangyin Chengxin is a leading alloy wire manufacturer in China. We offer a wide range of services, from fine wire drawing to resistance wire manufacturing. Our specialty lies in the quality and precision of our products, achieving the tightest tolerances and delivering orders within days to weeks. As a result, we have established ourselves as the premier supplier of alloy wire in the industry.

Our product range includes:

• Copper-nickel alloys (CuNi1-CuNi44)
• Karma (Nikrothal L/Evanohm/Alloy 800)
• Manganin and Constantan
• Nickel-chromium alloys
• Thermocouple alloys (Type K, N, E, T, J)
• Thermocouple extension wire
• PTC thermistor resistance alloy
• Pure nickel wire and Monel alloy

These alloys are available in various forms, including wire, ribbon, stranded, and enamelled. Major applications include seat heating, underfloor heating, military projects, aerospace, household appliances, heating wire, mechanical and electrical plants, and temperature instruments. Our manufacturing processes are ISO 9001:2015 certified, and we specialize in fine and ultra-fine wire drawing, offering wire diameters from 0.025 mm (0.001") to 13 mm (0.51") in small batches, medium volumes, and mass production. We maintain a comprehensive quality inspection system, including in-house chemical analysis, chromatographic analysis, metallurgical analysis, pinhole tests, wire construction tests, and tension tests to ensure the highest quality standards.

Senphus Electrical Material Co., Ltd.: Founded in 2003, Senphus Electrical Material Co., Ltd. integrates research, manufacturing, and sales of electric heating alloys, heating cables, heating wires, and heating products. Leveraging over a decade of technical expertise in heating alloy wire, we have adopted advanced heating cable technology and machinery, successfully developing heating cables, temperature controllers, and temperature control systems suitable for building heating, pipe insulation, outdoor snow melting, wind power blade production, car seat heating, and healthcare applications.

The company is recognized as a high-tech enterprise in Jiangsu Province and a small giant enterprise in Jiangyin City, specializing in innovative technologies. We operate the "Wuxi Heating Cable Engineering Technology Research Center" and collaborate with experts from renowned domestic universities. Our portfolio includes 5 invention patents and over 30 utility model patents, showcasing our strong research and development capabilities.

With an annual output exceeding 1,000 tons of thermal alloy wire and an output value of approximately 105 million yuan, our products are well-received in markets such as the UK, Italy, Canada, Peru, and Spain. Our heating cables generate an annual output value of over 80 million yuan, with exports to Germany, Japan, the United States, Malaysia, Denmark, Brazil, and other countries.

The company has successfully passed multiple quality management system certifications, including IATF 16949, ISO 9001, ISO 14001 (Environmental Management System), and ISO 45001 (Occupational Health and Safety Management System). Our heating cables and related products have also obtained test reports from the Shanghai Cable Research Institute Test Center and received certifications such as UL (United States), VDE (Germany), CE (European Union), and RoHS.

Commitment to Quality: We adhere to the business commitment of "Reputation First, Quality First, Customer First" and uphold the quality policy of "Integrity-Based, Quality-Oriented, Excellent Service." We are dedicated to providing accurate products and professional services, and we look forward to collaborating sincerely with you to achieve mutual success.