Type K Thermocouple

The type K is commonly found in nuclear applications because of its relative radiation hardness. 
Type K Thermocouple (Nickel-Chromium / Nickel-Alumel).
Maximum continuous temperature is around 1,100C. 
It’s inexpensive, accurate, reliable, and has a wide temperature range. 
Consideration for bare wire type K thermocouple application.
The type K is the most common type of thermocouple. 

Type K Thermocouple