| 摘要 |
PURPOSE:To accurately detect a liquid surface by winding a wire around a drum, forming a displacer sensing the liquid surface on the leading end of the wire and converting the tensile force of the wire due to the variation of the liquid surface into linear variation of a moving element. CONSTITUTION:The wire 2 is wound around the drum 1 and the displacer 3 is suspended and dipped on the liquid surface. A helical groove 15 is formed on the shaft 4 of the drum 1 to engage the moving element 27 of a magnet with the groove 15 with play. A rotary plate 17 is coupled with a motor 10 and guides 18, 19 are connected to the rotary plate 17 so as to be penetrated into the moving element 27. The movement is detected by a magnetic sensor 22 and the detected signal is inputted to the motor 10. The rotary plate 17 is rotated by the motor 10 to be balanced with the tensile force of the wire 2 so that the displacer 3 is dipped at a fixed level. The liquid surface is detected from the rotational frequency of the motor 10. Since the tensile force of the wire 2 is converted into the linear movement of the moving element, the liquid surface can be detected highly accurately. |
