| 摘要 |
PURPOSE:To easily detect foreign matter on a smooth surface by dewing the surface of a material which has the smooth surface and performing detection in the dew condensation state. CONSTITUTION:The smooth surface of the material to be observed is dewed by lowering the temperature below the dew point of ambient humidity. At this time, if foreign matter sticks on or in the surface of the material, e.g. if machine oil sticks on part of the surface of smooth copper, there is no dew condensation occurring there even after the machine oil is wiped away roughly, so the difference is detected. Thus, the foreign matter on the smooth surface is easily detected. |
