METHOD AND APPARATUS FOR DETECTING MELTING TIME POINT

摘要

PURPOSE:To enable to easily perform an accurate detection by moving detecting point of surface temperature detector by infrared rays on the surface of contents in the crucible and detecting a point of time when the difference of temperature of the surface due to the presence of unmolten material is eliminated. CONSTITUTION:Detecting point of the surface temperature detector 3 by infrared rays is moved on the surface of the contents 2 in the crucible 1 and perfect melting time point is determined by time having no difference in the temperature of surface due to the presence of the unmolten material 2b. For example, the crucible 1 is rotated centering around the vertical axis 1' and the temperature of surface of the contents 2 is monitored in one circumference of a circle. Then, the output of the detector 3 and that of the holding circuit 5 holding a mean output in detecting time partitioned by the timing circuit 4 of the output of the detector 3, are compared by the comparator 6 and a decision output is outputted as the perfect melting time point when there is no difference between both outputs.