| 摘要 |
PURPOSE:To enable the accurate detection of the micro-fluctuations of molten metal as well by so constituting the detector that a slit is provided ahead of a photoelectric tube and a condenser lens is provided ahead of the slit thereby making possible the detction of the molten metal level in a narrow visual field of detection. CONSTITUTION:A barrel 10 provided with a filter 11 and condenser lens 12 and a barrel 13 provided with a slit 14 are adjustably fitted and the barrel 13 and the barrel 16 fitted with a photoelectric tube 17 are mounted adjustable by means of a nut 15. The fluctuation value of the molten metal level within the visual field of detection for obtaining minimum illuminance required for the detection operation of the photoelectric tube 17 may be detected down to the much smaller fluctuation value on account of provision of the condenser lens 12. In addition, the light released when the molding sand near the molten metal level in the well part is heated red hot by the heat of the molten metal is cut off by a filter 11 and therefore the accurate level may be detected. |
