Utilizing Laser Technology in Dimensional Metrology Applications

The wavelength of light provides a very high resolution, linear, and stable reference for dimensional measurement. Labmaster® instruments effectively couple the wavelength of light to the part to be measured. They do this by using a fringe counting laser interferometer1 to detect linear motion of a probe that contacts the part (a mechanical comparison). Labmasters employ patented laser paths that are in-line with the measurement axis to minimize Abbe2 error. The probes and associated optics are guided along very accurate low friction slides by precision force systems to minimize instrument error. Although direct gage block interferometers (wringing a block to a platen) use the same principles, Labmaster systems offer the advantages of a protected environment for the light path, direct readout, faster operation, lower cost, and the ability to measure many different parts. Labmasters have accuracy's equivalent to short-range comparators but offer increased productivity due to their wide direct reading range. Although there are different methods for using a laser in measurement (such as Interferometry, triangulation, or scanning), Interferometry is typically orders of magnitude more accurate than other methods. Labmaster instruments use laser interferometers for the following reasons: