按惯例采用表面干涉仪测量平面度偏差。但当待测件严重变形时,会出现大量干涉条纹及封闭干涉环(图1～2),用干涉测量进行定量分类是困难的。由于其干涉条纹数目多,无法用目视进行快速计值,即使采用目前市售的位移法自动干涉计值系统也有困难。分辨率的标准是矩形探测面上的条纹密度至少需要每个条 Conventionally, surface interferometers are used to measure flatness deviations. However, when the test piece is seriously deformed, there will be a large number of interference fringes and closed interference rings (Figures 1 and 2). Quantitative classification by interferometry is difficult. Due to the large number of interference fringes, rapid visualization can not be performed, even with the current method of automatic interferometry of the displacement method. The standard for resolution is that at least one bar per bar is required for the stripe density on the rectangular detection plane