PURPOSE: To enable judging the level of the molten metal always accurately by a method wherein, after specifying a relationship among the temperature when a temperature detector is dipped in the a molten metal, the temperature when the temperature detector is exposed, and the preset temperature, the relationship between the temperature detected by the temperature detector and the preset temperature is read.
CONSTITUTION: Inside a melting vessel 6 which is capable of temperature control a temperature detector 10 is provided at a position making its heat-sensing element 11 come in contact with or away from the molten metal 2 according as the level 4, 5 of the molten metal rises or falls. To the temperature detector 10 a thermometer 12 with a preset comparator is connected. For this detective system a relationship expressed as Td>Tp>Te is set, wherein Td, Te, and Tp represent respectively the temperature when the temperature detector 10 is dipped in the temperature of a molten metal, the temperature when the temperature detector 10 is exposed, and a preset temperature. When the temperature detected by the temperature detector 10 during operation of the melting vessel 6 is above the preset temperature, the level 4 of the molten metal is judged to be above the heat-sensing element 11, whereas, when the temperature detected by the temperature detector 10 is below the preset temperature, the level 5 of the molten metal is judged to be below the heat-sensing element 11.
TANAKA MAKIO
HAYAKAWA YUKIHIRO
| JPS56151881A | 1981-11-25 |