Alumina oxygen sensor housing is a high-temperature ceramic body made from high-purity Al₂O₃ that supports and insulates the zirconia sensing element, heater and electrodes inside an oxygen sensor. It defines the internal geometry of the sensor stack, keeps the gas path and reference gap stable, and provides electrical insulation between conductive parts while working in hot exhaust or flue gas.
Specifications of Al2O3 Oxygen Sensor Housing
| Item No. | Diameter (mm) | Thickness (mm) | Purity |
| AT-AO-CG01 | Customize | ||
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Alumina Oxygen Sensor Housing Properties
This page supplies 95%, 96% and 99% alumina, all in IEC 60672-3 class C795. The grade is chosen for the assembly duty, then written on the drawing. Values below are material values used for grade selection.
| Property | Unit / condition | 95% AD-ALU-950 | 96% AD-ALU-960 | 99% AD-ALU-990 |
|---|---|---|---|---|
| Alumina content | Al₂O₃, wt%, nominal | 95 | 96 | 99.00 |
| IEC 60672-3 composition class | Composition grouping | C795 | C795 | C795 |
| Bulk density | g/cm³, typical | 3.75 | 3.70 | 3.80–3.91 |
| Flexural strength | MPa, 20 °C, typical | 280 | 300 | 300–320 |
| Thermal conductivity | W/(m·K), typical | 18–25 at 25 °C | 25 at 20 °C | 24 at 25 °C |
| Mean linear thermal expansion | 10⁻⁶/K, stated interval | 7.6; 25–800 °C | 8.2; 25–1000 °C | 7.2; 25–800 °C |
| Volume resistivity | Ω·cm, 20 °C | >10¹² | 10¹⁴ typical | >10¹⁴ |
| Dielectric strength | kV/mm, typical | 10; 5 mm | 8.3; AC, 6.35 mm | 10; 5 mm |
| Relative permittivity, εr | 1 MHz, typical | 9.4 at 25 °C | 9.0 at 25 °C | 9.6 at 25 °C |
| Dissipation factor, tan δ | 1 MHz | 0.0004 at 25 °C | 0.0002 at 20 °C | 0.0006 at 25 °C |
| Water absorption | %, selection limit unless stated | ≤0.20 | ≈0; typical, rounded | ≤0.10 |
| Service temperature guide | °C, application-dependent | 1400 | 1600 maximum in air | 1600 |
How to Choose an Alumina Oxygen Sensor Housing
Start with the sensor’s internal interfaces: seating position, bore levels, lead exits and electrical separation. Then select the housing form that matches the assembly.
- Shouldered or flanged holder
For axial positioning against a defined seat in the metal shell. Specify the shoulder diameter and height, seating datum and assembly direction. - Stepped-bore or slotted holder
For cells, heaters or electrodes positioned at different bore levels, or leads routed through openings. Define each bore diameter and depth, slot position and minimum wall thickness. - Compact insulating seat
For separating conductive parts at a contact or sealing face. Specify the insulation path, seating geometry and surface condition. - Closed-end or blind-bore body
For designs requiring a closed tip or internal cavity. Confirm the internal geometry through the drawing and approved sample; photographs show only the external form.
Alumina Grade Comparison for Oxygen Sensor Housings
Three grades are available on this page. Select the grade for the assembly’s operating conditions and record it on the approved drawing.
- AD-ALU-950 — General-purpose option
An economical choice for moderate operating conditions where electrical insulation and mechanical loads leave sufficient margin. Its listed resistivity and flexural strength are lower than those of the other two grades. - AD-ALU-960 — Balanced option
Offers strength and resistivity close to AD-ALU-990, with near-zero typical water absorption. Review its thermal expansion over the stated temperature interval, especially when assessing fit with surrounding components. - AD-ALU-990 — Higher-purity option
The highest-purity grade listed on this page. Consider it for stricter insulation requirements or closely controlled component positioning, with suitability confirmed against the actual temperature range and assembly geometry.
How to Choose
Review the temperature at the ceramic, atmosphere, insulation path and required fit. Higher purity alone does not guarantee better housing performance. Confirm the selected grade on the drawing and evaluate the sample against the assembly requirements.
How to Read the Material Values
- Strength and modulus: Material-specimen properties, not allowable loads for a finished housing with bores, slots or thin walls.
- Dielectric strength: A specimen value, not the finished housing’s working-voltage rating.
- Thermal expansion: Compare values over equivalent temperature intervals.
- Service temperature: A material-selection guide; confirm the housing’s operating limit for the complete assembly.
Higher-purity alumina can be reviewed for drawings with additional atmosphere or insulation requirements.
Alumina Oxygen Sensor Housing Packaging
- Each batch of alumina oxygen sensor housings is separated with soft, non-abrasive layers to avoid ceramic-to-ceramic contact during transit.
