Constantan is a type of resistance alloy primarily composed of copper and nickel. Known for its low temperature coefficient of resistance (TCR) and broad operating temperature range (below 500°C), it is highly valued for its mechanical workability and excellent corrosion resistance. Due to these properties, Constantan is widely used in variable and strain resistance elements for alternative instruments.
Manganin, a copper-manganese-nickel resistance alloy, combines all the critical characteristics of a precision electrical resistance alloy. It offers high resistivity, low TCR, minimal thermal effects against copper, and stable electrical resistance over prolonged periods. These properties make Manganin ideal for use in precision instruments and electrical components.
Key Technical Characteristics of Constantan and Manganin Alloys
Grade | CONSTANTAN 6J12 | MANGANIN 6J8 | MANGANIN 6J13 | MANGANIN 6J40 |
Main Chemical Composition (%) | ||||
Mn | 1~2 | 11~13 | 8~10 | 11~13 |
Ni | 39~41 | 2~3 | - | 2~5 |
Cu | Balance | Balance | Balance | Balance |
Max Working Temperature (°C) | 5~500 | 5~45 | 10~80 | 10~81 |
Density (g/cm³) | 8.88 | 8.44 | 8.70 | 8.40 |
Resistivity (μΩ·cm) | 0.48±3% | 0.47±3% | 0.35±5% | 0.44±4% |
Elongation (%) | ≥15 | ≥15 | ≥15 | ≥15 |
Resistance Temperature Coefficient (TCR, ppm/°C) | -40~+40 | -3~+20 | -5~+10 | 0~+40 |
Thermo EMF (μV/°C) | 45 | 1 | 2 | 2 |
Optimized Uses of Constantan and Manganin
Constantan (6J12): Its consistent performance in high-temperature environments (up to 500°C) and low TCR make it ideal for applications requiring stable resistance over varying temperatures.
Manganin Grades (6J8, 6J13, 6J40): With superior resistivity and low thermal effects, Manganin alloys are particularly suited for precision measurement devices, offering long-term reliability and stable resistance. Each grade provides specific performance characteristics tailored to different resistance requirements.
In conclusion, both Constantan and Manganin alloys offer outstanding performance in electrical and precision measurement applications. Constantan excels in environments requiring durability and corrosion resistance, while Manganin is the alloy of choice for long-term, stable electrical resistance.