Metrology & Measurement

The author gives an overview of the most common hardness testing methods: Rockwell, Brinell, Vickers and Knoop.

With close-tolerance machining, variances in the temperature of the part or gage can lead to out-of-tolerance work. This article describes the compensation systems that have been developed to measure temperatures and make the necessary adjustments to gage readings.

Next-generation CMM software offers users a simple interface, the ability to program the machine directly from CAD data files and the opportunity to write programs off-line. This article describes the latest advancements in CMM software and shows how older machines can be retrofitted to take advantage of the software's features.

When digital calipers that did not have to be zeroed before each measurement were introduced, they represented a significant advancement in electronic gaging. This article explains the technology behind these absolute-reading instruments and how they are used to make typical shop-floor measurements.

Casting a pattern of light on a part and viewing that pattern at a different angle through a grating with the same pattern creates a moire pattern that can reveal small changes in the part's shape. This article tells how this phenomenon can be used by machine vision systems to measure part dimensions or pinpoint variations from a specified contour.

Software-based video tool inspection systems can read tool geometries much more precisely than other measurement systems. This article looks at the technology behind these systems and explains how this technology detects and measures tool edges and angles.