Original
By certification 
Alumina ceramic protection tubes have good mechanical strength, wear resistance, corrosion resistance and good air tightness, so they are excellent primary protection tubes. Alumina ceramic protection tubes can be used for primary and secondary protection tubes on precious metal (platinum-based) thermocouples.
Materials Physical and Chemical Index
| Item | Unit |
AL99.7% |
AL99 |
AL95 |
Al2O3 content |
— |
99.7% |
99% |
95% |
Color |
— |
Ivory white |
Ivory white |
Ivory white，white |
Air tightness |
— |
airtight |
airtight |
airtight |
Density |
g/cm3 |
3.94 |
3.8 |
3.7 |
Straightness |
— |
2‰ |
2‰ |
2‰ |
hardness |
Moh's hardness |
9 |
9 |
8.8 |
Water absorption |
≤0.2 |
≤0.2 |
≤0.2 |
≤0.2 |
Flexural strength（20℃） |
Mpa |
375 |
340 |
304 |
Compressive strength（20℃） |
Mpa |
2300 |
2210 |
1910 |
Thermal expansion coefficient（25℃-800℃） |
105/℃ |
7.6 |
7.6 |
7.6 |
Insulation strength（thickness:5mm) |
AC-kv/mm |
10 |
10 |
10 |
Dielectric loss 25℃@1MHz |
— |
<0.0001 |
<0.0006 |
<0.0004 |
Volume resistivity |
Ω·cm3 |
>1014 |
>1014 |
>1014 |
Long-term use temperature |
℃ |
1700 |
1600 |
1200 |
Thermal conductivity（25℃） |
W/moK |
35 |
34 |
20 |
Regular dimension
●Outer diameter: 3mm-25mm;
●Maximum length 2500mm;
●Thickness: by dimension scale of product 0.5mm to 4mm.
●Customized size is available
Why choose us?
1.We are a manufacturer of advance ceramic tubes, with 15 years of export experience.
2.Perfect workmanship. Always committed to research and development.
3.We will reply to you within 24 hours.
4.The samples will supply you for free.
5.Ensure the goods will be delivered on time.
6.OEM, customized designs, sizes, and logos are acceptable.
http://www.koceramic.com/
