Carbolite HTF Series - Manual (Page 7)

RHF & HTF
MF22 3.09
7
3.6 Thermocouples - Warning
(1) The output from 1700-1800°C thermocouples when used regularly at temperatures greater than
1650°C can deteriorate and decrease with age.
Customers are advised periodically to check the thermocouple output, either by a calibration test,
or by comparing the output with a new reference thermocouple which has been subjected to high
temperatures for a minimum length of time.
Failure to check the thermocouple may result in overheating of the work and the furnace.
(2) The thermocouples fitted to these models give very low outputs below about 600°C, and do not
give accurate readings at low temperatures. The furnaces are not intended to be operated below
600°C.