Platinum (Pt) belongs to both the refractory as well as the noble metals. Noble metals are highly resistant to chemical attack, even at high temperatures. While refractory metals are extremely heat resistant and highly durable. These factors, combined with excellent thermo-electric properties, makes platinum an ideal sheath material for temperature control in highly demanding environments.
With the addition of rhodium (Rh) as a 10% or 20% alloy, all these favorable characteristics of platinum are preserved while improving the mechanical strength at higher operating temperatures.
Furthermore, in comparison to ceramic sheaths, platinum and its alloys are much more flexible which is a very useful characteristic when placing thermocouples in intricate spaces.
Platinum 10% rhodium
|Composition||PT 90%, Rh 10%|
|Melting point||1840°C to 1870°C|
|Maximum operating temperature||1700°C|
Platinum 20% rhodium
|Composition||PT 80%, Rh 20%|
|Maximum operating temperature||1800°C|
Other physical properties include:
Platinum alloy sheaths are suited to oxidizing and inert environments or any intensely corrosive conditions. Some of the industries where they are used include:
|Min OD (mm)||Max OD (mm)||TC type possible (type)|
|Pt10%Rh||1.00||4.78||K, J, B, R, S|
|Pt20%Rh||1.00||4.78||K, J, B, R, S|
Kamet supplies Pt10%Rh and Pt20%Rh thermocouple sheaths of excellent quality.
As experts in sheath materials we are able to assist you with any questions you might have. Thanks to our large network of global manufacturers we offer a wide range of MI cable and thermocouples with special sheath materials. A range of customization options is available for any unique challenges, so please feel free to contact us.