10 inch model

The very best thermocouple for constant high fire applications is a Type S platinum thermocouple with an alumina sheath.

This is normally only recommended for the most extreme conditions (like firing crystalline glazes) because of its expense - or if the value or precision of your work is such that you do not want to risk thermocouple drift.

Be sure you set your electronic controller for type S if you are now using type k. This is very important if you do not you will burn up your kiln.