Patent ID: 6837619

Claim:
A furnace temperature detector, comprising: a spike thermocouple attached to a heating chamber; an overheat thermocouple attached to the heating chamber; an inner thermocouple installed inside a reaction tube surrounded by the heating chamber; a temperature controller connected to an output line of the spike thermocouple and an output line of the inner thermocouple; an overheat controller connected to an output line of the overheat thermocouple; and a control switch for directing the output line of the overheat thermocouple, wherein: when the furnace is operating in an overheating state, the overheat thermocouple detects the overheating state of the furnace and generates and outputs an electric signal corresponding to the overheating state of the furnace to the overheat controller, and the overheat controller generates and outputs an overheat control signal; and when the furnace is operating without reaching the overheating state, the overheat thermocouple detects a furnace temperature and generates and outputs an electric signal corresponding to the furnace temperature to the control switch, the control switch directs the output line of the overheat thermocouple to the temperature controller, and the temperature controller generates and outputs a temperature control signal.