Application of the Two-Beam Interference Microscope to the Study of Surfaces

Abstract

Interference microscopes that have recently become available have overcome many of the operational difficulties previously experienced. As a result, the two-beam interference microscope is finding increasing use in the laboratory in the study of surface topography. Present instruments are capable of examining surface detail in the range of 2 to 100 microinches peak-to-valley. A number of applications to the study of surfaces important in industry are presented. These include: (1) the measurement of thickness of electrodeposited coatings, (2) the study of the leveling properties of electrodeposits, (3) measurement of the erosion or shrinkage of paint films upon weathering, (4) investigation of hardness measurement indentations, (5) examination of industrial sheet-steel finishes, and (6) control of the geometry of accurate surface roughness standards. Replica techniques which make it possible to use the instrument to study curved and inaccessible surfaces are also discussed.