Method and apparatus for evaluating properties of carbon fibers using capacitance sensing

摘要

A method and apparatus are provided for nondestructively evaluating physical properties of materials, and particularly semiconductive or electrically conductive fibers, e.g., carbonaceous fibrous materials containing at least about 90 per cent carbon by weight. The material is disposed in spaced relationship to a test electrode in an electrolytic solution and the physical property of the fiber is evaluated by evaluating the capacitance of the material. This capacitance evaluation may then be compared to the capacitance evaluation of a reference material having predetermined physical properties with the results of the comparison indicating the properties of the tested material. This indication may be utilized in the quality control of manufactured fibers by manual or automatic adjustment of the manufacturing process conditions. In fiber experimentation, this indication may be utilized to provide an evaluation of the effectiveness of an experimental process.