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The 95%/99% Alumina Ceramic Thermocouple Insulator is a high-temperature insulating component made from alumina (Al₂O₃) ceramic. Designed for Type K thermocouple assemblies in industrial furnaces, kilns, heat-treatment equipment, and temperature-monitoring systems, it separates and supports thermocouple wires. Its electrical insulation, thermal stability, and mechanical strength help prevent wire contact, short circuits, and unstable measurements during prolonged exposure to high temperatures.
Alumina ceramic thermocouple insulators are widely used in temperature measurement and heating control systems, especially where thermocouple wires need reliable separation and protection.
| Technical Parameter | 95% Alumina Ceramic | 99% Alumina Ceramic |
|---|---|---|
| Alumina Content | ≥95% Al₂O₃ | ≥99% Al₂O₃ |
| Bulk Density | Approx. 3.75 g/cm³ | Approx. 3.80 g/cm³ |
| Maximum Continuous Operating Temperature | Approx. 1450°C | Approx. 1600°C |
| Flexural Strength | Approx. 300 MPa | Approx. 340 MPa |
| Thermal Conductivity at Room Temperature | Approx. 16 W/(m·K) | Approx. 24 W/(m·K) |
| Dielectric Strength | Approx. 16 kV/mm | Approx. 19 kV/mm |
| Volume Resistivity at Room Temperature | ≥10¹⁴ Ω·cm | ≥10¹⁴ Ω·cm |
| Water Absorption | ≤0.01% | ≤0.01% |
| Standard Bore Structure | Twin-bore | Twin-bore |
| Optional Bore Structures | Single-bore, twin-bore, four-bore, or custom multi-bore | Single-bore, twin-bore, four-bore, or custom multi-bore |
| Material | High-Temperature Insulation | Mechanical Strength | Chemical Stability | Relative Cost | Recommended Applications |
|---|---|---|---|---|---|
| 95% Alumina Ceramic | Very good | High | Very good | Medium | General industrial Type K thermocouples and furnace temperature monitoring |
| 99% Alumina Ceramic | Excellent | High | Excellent | Higher | High-temperature, vacuum, or purity-sensitive thermocouple applications |
For most industrial Type K thermocouples, 95% alumina ceramic provides a practical balance of electrical insulation, mechanical strength, and cost. The 99% grade is recommended when higher-temperature stability, chemical resistance, or material purity is required.
1. What role does an alumina ceramic insulator play in a Type K thermocouple?
It separates, supports, and protects the positive and negative thermocouple wires, helping prevent wire contact, short circuits, and unstable measurement signals in high-temperature environments.
2. What is the difference between 95% and 99% alumina ceramic?
The 95% grade provides a practical balance of electrical insulation, mechanical strength, and cost for general industrial applications. The 99% grade offers higher purity, better high-temperature insulation, and greater chemical stability for more demanding environments.
3. Why is alumina ceramic commonly used for thermocouple insulators?
Alumina ceramic provides reliable electrical insulation, high-temperature resistance, mechanical strength, and chemical stability, enabling it to support and isolate thermocouple wires in furnaces and heat-treatment equipment.
4. What bore structures and internal-hole requirements can be customized?
Single-bore, twin-bore, four-bore, and custom multi-bore structures are available. Bore diameter, spacing, position, end geometry, and internal surface requirements can be evaluated according to the thermocouple wire and assembly design.
5. Can the dimensions and structure be customized according to drawings?
Yes. Outer diameter, length, tolerances, end faces, chamfers, and segmented structures can be customized according to customer drawings, samples, or assembly requirements.
6. What equipment commonly uses these ceramic insulators?
Typical applications include industrial furnaces, kilns, heat-treatment equipment, laboratory heating systems, injection-molding machines, battery-testing systems, and industrial temperature-monitoring equipment.
Please provide material grade, outer diameter, inner bore size, number of holes, length, quantity, working temperature and drawings if available. You can send details through our contact page.
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