Eddy current thickness measurement apparatus

摘要

A sheet of a material is disposed in a melt of the material. The sheet is formed using a cooling plate in one instance. An exciting coil and sensing coil are positioned downstream of the cooling plate. The exciting coil and sensing coil use eddy currents to determine a thickness of the solid sheet on top of the melt.

主权项

1. A sheet-forming apparatus comprising:
a melt of a material; a sheet of said material disposed in said melt, wherein said sheet has a higher resistivity than said melt; a cooling plate disposed a distance above a surface of said melt that is configured to form said sheet; an eddy current measurement system for providing real-time monitoring and feedback of a thickness of said sheet as it is formed in said melt, the eddy current measurement system comprising: an exciting coil and a sensing coil disposed a second distance above said surface of said melt downstream of said cooling plate; and a power source connected to said exciting coil; and a controller connected to said eddy current measurement system, said controller programmed to execute instructions to increase a temperature of said cooling plate if said sheet is thicker than desired and to decrease a temperature of said cooling plate if said sheet is thinner than desired.