Overheating of the crown in a glass melter, promotes accelerated refractory corrosion and wear.
Operating a crown at too low a temperature, on the other hand, may reduce melting efficiency and increase fuel consumption. 

Crown thermocouples provide important data on the operating temperature of the melter, regenerator and refiner. Determination and control of the melter hot spot, essential for effective glass circulation, can be readily achieved by placing a number of crown thermocouples along the centre of the arch. A reliable sensor will also provide the necessary data to prevent potentially destructive over temperature conditions to occur.