Accurate And Stable Type T Thermocouple Wire Positive Leg Cu(TP) For Scientific Research And Humidity Resistance
Type T thermocouple wire consists of Copper (Cu, TP) as the positive leg and Constantan (Cu-Ni alloy, TN) as the negative leg. It is widely used for low-temperature measurements, offering high accuracy and stability. The Type T thermocouple's positive leg, composed of pure copper (Cu(TP)), is a critical component in cryogenic and low-temperature measurement systems. As one of the most stable thermoelectric materials, Cu(TP) offers a linear output voltage of approximately 43 μV/°C over its operational range of -200°C to 350°C (some specialized grades up to 400°C). The high purity copper (≥99.95%) ensures excellent thermal conductivity and minimal resistance variation, making it ideal for precise temperature sensing in environments like refrigeration systems, food processing, and medical devices.
Name | TP | TN |
Melting Range(℃) | 1084 | 1220 |
Density(g/cm³) | 8.9 | 8.8 |
Resistivity(μΩm20℃) | 1.71 | 49 |
Resistance-temperture coefficient ×10-4/K(0℃-1200℃) | 43 | 0.5 |
Tensile strength Rm N/mm² MPa | ≥196 | ≥390 |
Elongation % | ≥30 | ≥25 |
Composition & Properties:
- Positive Leg (TP): Pure Copper (~99.9%)
- Temperature Range: -200°C to 350°C
- Accuracy: ±1.0°C or 0.75% (Standard), ±0.5°C or 0.4% (Special)
- Electrical Conductivity: High (similar to pure copper)
- Corrosion Resistance: Good in dry air but prone to oxidation in humid environments
- EMF Output: ~40.69 µV/°C at 0-100°
Thermocouple temperature range and tolerance
Name | Usag Classification | Grade | Max. operating temperature(℃) | emperitre nres) | Tnlerene | Standard |
Lang term | Short term |
Cu-CuNi (Type T) thermocouple bright wire | T | l, Ⅱ | 300 | 350 | -40~350 | ±0.5℃ or ±0.4%t ±1℃ or ±0.75%t | GB/T4994 ISO 14125 |
Ⅲ | -200~40 | ±2.5℃ or ±0.75%t |
Key Features of Type T Positive Leg (Cu, TP):
- Material Composition: 99.9% pure copper
- Temperature Range: -200°C to 370°C (-328°F to 698°F)
- Electrical Conductivity: High, as it is made of pure copper
- Corrosion Resistance: Good resistance to oxidation in moist environments
- Thermoelectric Stability: Excellent for cryogenic and laboratory applications
- Accuracy: ±0.5°C or better in standard limits of error (IEC 60584, ASTM E230)
- Compatibility: Works with the Constantan (Cu-Ni) negative leg (TN)
- Color Code:
ANSI/IEC: Blue outer jacket, Copper-colored positive lead
Applications
- Cryogenics & Refrigeration (low-temperature monitoring)
- Biomedical & Laboratory Equipment
- Food Processing & Cold Storage
- Environmental Monitoring Systems
Key Advantages:
- High Precision: Stable output at cryogenic temperatures
- Good Conductivity: Fast response time
- Cost-Effective: Compared to noble metal thermocouples
- Non-Magnetic: Suitable for sensitive environments
Limitations:
- Limited High-Temperature Use – Oxidation risk above 350°C
- Copper Susceptibility – Requires proper insulation to prevent interference
Type T thermocouple with Cu (TP) positive leg is ideal for precise low-temperature measurement applications, ensuring reliable performance in demanding environments.
- Accuracy at Low Temperatures: Type T is one of the most accurate thermocouples in the low-temperature range.
- Non-Magnetic: This feature makes it ideal for sensitive applications, such as medical equipment or precision instruments.
- Corrosion and Oxidation Resistance: Excellent performance in humid and moisture-rich environments due to the corrosion resistance of the Constantan leg.
- Stable Performance: Offers low drift and good long-term stability, making it reliable for applications that require consistent results.
Limitations:
- Limited High-Temperature Range: Type T is not suitable for high-temperature environments (above 350°C), limiting its use in industrial applications that require higher temperatures.
- Oxidation of Copper Leg: The copper leg can oxidize at higher temperatures, reducing the lifespan of the thermocouple if exposed to high-temperature or oxidizing environments.
- More Expensive Than Other Thermocouples: Due to its high sensitivity and specialized use, Type T can be more expensive compared to other common thermocouples like Type K.


