The Appreciation of the Machined Surface by Total Reflection Method

The working principle and experimental results about the measurement of contact area between metal and transparent material by the aid of total reflection of polarized ray were already reported (Kikaishikensho-shoho, 6, 1954, 215).A Considerably complete testing apparatus was designed as illustrated in Fig. 2. It simplified the operation of angle of incidence and the loading mechanism, etc. At first, such a measuring limit as recognized to be in contact was investigated. A pair of block gauges, having the difference of several microns of thickness between two gauges, was placed on an optical flat plate, and a glass prism was pressed on to them. It was clarified that the least distance to be discriminated was 0.02-0.03 as seen in Fig.3. Then some surfaces of machined parts were tested by this apparatus and the contact ratio concerning lapped cylinders was measured. From the series of experiments, designing conditions of apparatus for practical use were decided.