08-10-2012, 05:40 PM
Engineering Metrology and Instrumentation
Engineering Metrology.ppt (Size: 3.51 MB / Downloads: 152)
Machine-Tool Slideway
Figure 35.1 Cross-section of a machine-tool slideway. The width, depth. Angles, and other dimensions all must be produced amd measured accurately for the machine tool to function as expected.
Analog and Digital Measuring Devices
Figure 35.2 (a) A vernier (analog) micrometer. (b) A digital micrometer with a range of 0 to 1 in. (0 to 25 mm) and a resolution of 50 μin. (1.25μm). It is generally easier to read dimensions on this instrument compared to the analog micrometer. © Schematic illustration showing the integration of digital gages with microprocessors for real-time data acquisition for statistical process control. Source: (a) Courtesy of L.C. Starret Co. and (b) Courtesy of Mitutoyo Corp.
Measuring Flatness
Figure 35.6 (a) Interferometry method for measuring flatness using an optical flat. (b) Fringes on a flat, inclined surface. An optical flat resting on a perfectly flat workpiece surface will not split the light beam, and no fringes will be present. © Fringes on a surface with two inclinations. Note: the greater the incline, the closer together are the fringes. (d) Curved fringe patterns indicate curvatures on the workpiece surface.
Air Gages
Figure 35.11 (a) Schematic illustration of the principle for an air gage. (b) Three types of plugs used for air gaging. The gage on the right is an air snap gage. © A conical head for air gaging; note the small air holes on the conical surface. Source: (b) Courtesy of Mahr Federal Inc. © Courtesy of Stotz Gaging Co.