| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly accurate determination method of a three-dimensional distribution of a surface roughness of a silica glass crucible.SOLUTION: According to the invention, a determination method of a three-dimensional distribution of a surface roughness of an internal surface includes steps of: moving an internal range finding part along the internal surface of a silica glass crucible in a non-contact manner; emitting a laser beam from the internal range finding part to the internal surface of the silica glass crucible in an oblique direction at multiple measurement points on a movement route; changing a distance between the internal range finding part and the internal surface or an emission direction of the laser beam such that two peaks can be observed by measuring reflected light of the laser beam using a laser displacement guage so that an internal surface distance between the internal range finding part and the internal surface is measured with a peak position on an internal surface side among the two peaks; determining a three-dimensional shape of the internal surface of the silica glass crucible by associating a three-dimensional coordinate of each measurement point with the internal surface distance; and determining three-dimensional distribution of the surface roughness of the internal surface by measuring the surface roughness of the internal surface at multiple measurement points on this three-dimensional shape. |
