APPARATUS FOR DETECTING A FLAW OF BILLET

摘要

An apparatus for detecting a crack of a billet is provided to maintain an infrared ray optical element at optimal temperature without installing a separate external cooling device. An apparatus for detecting a crack of a billet comprises: an infrared ray optical element(20) maintaining the optimal temperature with an electron cooling method in response to cooling current; and a temperature controller(30) generating the cooling current and compensating for the temperature of the infrared ray optical element after detecting the temperature of the infrared ray optical element. The infrared ray optical element has the temperature difference corresponding to the crack of the billet. The infrared ray optical element receives the infrared ray which is income and converts the infrared ray into electric signals. The temperature controller comprises: a comparison unit comparing varied voltage according to the temperature of the infrared ray optical element with the reference voltage; and a cooling current generating unit providing cooling current to the infrared ray optical element. The cooling current generating part generates the cooling current corresponding to the output voltage of the comparison unit.