Difference between Thermocouple grade and extension grade wire ?

Posted on 6th January 2025

Feature	Thermocouple Grade Wire	Extension Grade Wire
Purpose	Used in the thermocouple itself for sensing temperature.	Used to extend the connection to the measuring instrument.
Material Composition	Made from high-quality alloys with precise thermoelectric properties.	Made from alloys that mimic thermocouple alloys but with lower-grade materials.
Accuracy	Manufactured for high accuracy, meeting strict standards.	Less accurate, used to carry signals over longer distances.
Temperature Range	High temperature resistance (up to 2500°C or more, depending on type).	Lower temperature range, typically up to 200°C-300°C.
Applications	Used directly in thermocouple temperature sensors and probes.	Used for connecting thermocouples to temperature measurement devices.
Cost	More expensive due to high material quality and precise calibration.	Less expensive than thermocouple grade wire.