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Constantan® Foil (Light Tight)
Available Configurations
Properties common to all products in this list
| Thickness | Sides | Temper ⓘ | Other Variant |
|---|---|---|---|
| 0.005mm (foil) to 1mm (sheet) | 6mm to 1000mm | As rolled Annealed |
Non Light Tested |
Need custom configurations? Please contact us.
Health hazard/Hazardous to the ozone layer
Serious health hazard
Key Features
Constantan® Foil (Light Tight) (Cu55/Ni45) is a copper-nickel alloy foil with a nominal composition of 55% copper and 45% nickel, engineered for stable electrical performance and complete opacity to external light:
Near-Zero Temperature Coefficient of Resistance with Complete Light Exclusion
Constantan® Foil (Light Tight) combines a near-zero temperature coefficient of resistance with low thermal EMF against copper, making it highly reliable in precision measurement environments — while its complete opacity to external light extends this resistive stability into applications requiring simultaneous optical isolation.
Light-Tight Construction Critical for Optical Instrumentation & Photodetector Housings
The light-tight characteristic ensures no light penetration, which is critical for applications in optical instrumentation, photodetector housings, and strain measurement systems where light interference can distort readings — protecting sensitive optical and electrical measurements from unwanted illumination.
Low Thermal EMF Against Copper Preserved in the Light-Tight Format
Low thermal EMF against copper is preserved in the light-tight foil format, ensuring that Constantan® Foil (Light Tight) delivers the same precision measurement reliability as standard constantan foil while adding the optical isolation required in light-sensitive instrumentation environments.
Trusted Across Aerospace, Electronics & Metrology for Light-Shielded Sensing Applications
Industries including aerospace, electronics, and metrology rely on this foil for use in light-shielded strain gauges, encapsulated Wheatstone bridge circuits, and resistance standards in sensitive environments — where both resistive stability and optical isolation are simultaneous design requirements.
Stable Resistivity Combined with Optical Opacity for Optoelectronic Instrumentation
Constantan foil (light tight) combines stable resistivity with optical opacity for light-shielded strain gauges, resistive circuits, and precision optoelectronic instrumentation — providing a single material solution for applications that would otherwise require separate resistance alloy and light-shielding components.
Industrial Applications
Constantan® Foil (Light Tight) is used across aerospace, electronics, and metrology applications wherever precision resistive sensing must be combined with complete optical isolation:
- ✦ Light-Shielded Strain Gauges
- Used in light-shielded strain gauges, where Constantan® Foil (Light Tight)'s combination of stable resistivity and complete light exclusion ensures accurate strain measurement in optically sensitive environments where ambient light could otherwise interfere with adjacent photodetector or optical measurement systems.
- ✦ Encapsulated Wheatstone Bridge Circuits
- Applied in encapsulated Wheatstone bridge circuits, where the foil's low thermal EMF against copper and near-zero temperature coefficient of resistance provide stable bridge circuit performance within a light-excluding encapsulation required for sensitive measurement applications.
- ✦ Resistance Standards in Sensitive Environments
- Used as resistance standards in sensitive environments, where the combination of predictable, stable resistive behavior and complete optical opacity ensures that the resistance reference is not compromised by light-induced effects in optically sensitive calibration or measurement settings.
- ✦ Optical Instrumentation & Photodetector Housings
- Used in optical instrumentation and photodetector housings, where light interference can distort readings, with Constantan® Foil (Light Tight)'s light-tight construction ensuring no light penetration while simultaneously providing stable resistive performance for any integrated electrical measurement function.
- ✦ Precision Optoelectronic Instrumentation Requiring Resistive Circuits
- Used in precision optoelectronic instrumentation requiring resistive circuits, where Constantan® Foil (Light Tight) combines stable resistivity with optical opacity in a single component — supporting light-shielded resistive circuit design without the need for separate resistance alloy and light-shielding materials.
Material Properties
| Element | Value |
|---|---|
| Hardness - Brinell | 100-300 |
| Elongation at break( % ) | 45 |
| Modulus of elasticity( GPa ) | 162 |
| Izod impact strength( J m⁻¹ ) | 107 |
| Tensile strength( MPa ) | 400-590 |
| Element | Value |
|---|---|
| Electrical resistivity( µOhmcm ) | 52 |
| Temperature coefficient( K⁻¹ ) | 0.00002+/- |
| Element | Value |
|---|---|
| Maximum use temperature in air( C ) | 500 |
| Melting point( C ) | 1225-1300 |
| Thermal conductivity( W m⁻¹ K⁻¹ ) | 19.5@23°C |
| Coefficient of thermal expansion( x10⁻⁶ K⁻¹ ) | 14.9@20-100°C |
| Element | Value |
|---|---|
| Density( gcm⁻³ ) | 8.9 |
Tolerances
| Thickness | <0.01mm | ±25% |
|---|---|---|
| Thickness | 0.01mm - 0.05mm | ±15% |
| Thickness | >0.05mm | ±10% |
| Linear dimension | <100mm | ±1mm |
| Linear dimension | >=100mm | +2 / -1% |