Type K Thermocouple Bare Wire (KP/KN) – 3.2mm Diameter Heavy-Duty
Grade
Product Overview
This heavy-gauge Type K thermocouple bare wire from Huona is a
robust, industrial-grade thermoelectric wire pair composed of KP
(Chromel, positive leg) and KN (Alumel, negative leg), specifically
engineered for long-term, high-temperature industrial applications.
Manufactured via precision vacuum melting, heavy-gauge drawing, and
stress-relief annealing, this thick wire delivers exceptional
mechanical strength, resistance to thermal fatigue, and stable
thermoelectric performance, making it ideal for furnace monitoring,
kiln controls, and power plant processes.
Core Specifications
- Product Name: Type K Thermocouple Bare Wire (KP/KN Pair,
Heavy-Duty)
- Alloy Composition:
- KP (Positive Leg): Chromel (Ni: ~90%, Cr: ~10%)
- KN (Negative Leg): Alumel (Ni: ~95%, Al: ~2%, Mn: ~2%, Si: ~1%)
- Diameter: 3.2mm (customizable: 2.0–6.0mm)
- Tolerance: ±0.02mm
- Form: Coil (standard length: 25m/leg; custom lengths available)
- Thermoelectric Performance:
- Accuracy Class: IEC Class 1 (±1.5°C or ±0.4% of reading, whichever
is greater)
- Thermoelectric Power: ~40.5 µV/°C at 100°C
- Operating Temperature Range: -200°C ~ 1260°C (continuous use;
long-term service life enhanced at 1000–1200°C)
- Standards Compliance: IEC 60584-1, ASTM E230, GB/T 4989, RoHS 2.0
- Manufacturer: Huona (Shanghai) New Material Co., Ltd.
Key Differentiating Advantages
1. Extended Service Life in High-Temperature Environments
The heavy 3.2mm diameter significantly slows the rate of oxidation
and “green rot” degradation at temperatures above 1000°C, doubling
the service life compared to thinner (≤1.0mm) Type K wires. This
reduces maintenance and replacement costs in continuous-process
industrial furnaces.
2. Superior Mechanical Strength & Thermal Fatigue Resistance
With a tensile strength ≥700 MPa and robust cross-sectional area,
this wire resists sagging, deformation, and breakage in vertical
furnace installations and under repeated thermal cycling. It
eliminates the risk of wire fatigue common with fine-gauge wires in
high-vibration environments.
3. Reduced Signal Drift & Stable Long-Term Readings
The larger cross-sectional volume of the heavy-gauge wire minimizes
thermoelectric drift caused by alloy phase changes and
contamination, ensuring consistent, accurate readings even after
thousands of hours of continuous high-temperature use.
4. Enhanced Weldability & Probe Assembly Compatibility
The thick wire diameter provides ample material for robust junction
welding, simplifying the construction of heavy-duty,
high-temperature thermocouple probes. It is also compatible with
standard ceramic protection tubes and terminal connections for
industrial installations.
5. Low Maintenance for Continuous Process Monitoring
Designed for minimal calibration and replacement needs, this
heavy-duty wire is ideal for “fit-and-forget” temperature
monitoring in power plants, steel mills, and glass manufacturing
facilities where process uptime is critical.
Technical Specifications Table
| Attribute | Value (Typical) |
|---|
| Alloy Grade | KP (Chromel) / KN (Alumel) |
| Diameter | 3.2mm (±0.02mm) |
| Form | Coil |
| Accuracy Class | IEC Class 1 |
| Operating Temperature | -200°C ~ 1260°C (continuous) |
| Tensile Strength | ≥700 MPa (KP/KN) |
| Elongation | ≥20% |
| Surface Finish | Oxidized dark finish (standard for high-temperature use) |
| Packaging | Anti-oxidation coil packaging with moisture-proof wrapping |
Typical Applications
- Industrial Furnaces & Kilns: Long-term temperature monitoring
in steel reheat furnaces, ceramic kilns, and glass melting
processes.
- Power Generation: Boiler and steam turbine temperature monitoring
in coal-fired and gas-fired power plants.
- Metallurgical Processing: Temperature control in metal heat
treatment, casting, and forging operations.
- Petrochemical Refining: High-temperature monitoring in process
heaters, reformers, and catalytic cracking units.
- Heavy Machinery: Engine exhaust and industrial boiler temperature
sensing in power generation and manufacturing equipment.
