The Evaluation Method of Surface Roughness Degree for Long-Term Operating Conductors Based on Gray Value Matrix

In order to obtain the average surface roughness R a of the long-term operating conductors in service, the features of 2-D surface morphologies were investigated based on the gray value matrix G. The neighborhood averaging method was utilized in obtaining G. In a wide range of R a, a linear relationship was discovered between the variance F and R a. Therefore, R a could be obtained based on the images from the camera and G without the need to dismantle the conductors in service, and it is more time saving and economical for the measurements.