George Schuetz Director of Precision Gages

1 Nov 1998

Measuring Roughness With Buttons And Donuts

The Ra parameter is the most commonly used measurement for surface roughness. Until recently, in fact, it was the only parameter recognized by ANSI, although new ANSI and ISO standards include many different parameters from which to choose.

1 Oct 1998

A Shallow Bore (This Is Not An Autobiography)

Imagine a large rotor with an ID of 12 inches. One normally uses an adjustable bore gage, or perhaps an inside rod micrometer, to check the diameter.

1 Sep 1998

Take A Stand

Bench comparators consist of an indicating device, plus a height stand that incorporates a locating surface for the part. On some stands—especially those used to measure large parts—the base itself serves as the reference surface.

1 Aug 1998

Temperature Compensation

Temperature variation is one of the most significant sources of gaging error. As manufacturing tolerances get tighter and the margin for gaging error gets smaller, it becomes an issue that must be addressed.

1 Jul 1998

Central Intelligence

Many factors influence the accuracy of hole diameter measurements. We've seen in past columns the importance of operator skill in the use of rocking-type adjustable bore gages, and discussed how variations in part geometry may make even technically accurate measurements inaccurate from a part-function perspective.

Basics 1 Jun 1998

How to Correct for Cosine Error

A small shopfloor network lays the groundwork for large-scale, low-cost DNC throughout a major manufacturing facility.

Basics 1 May 1998

Electronic Gaging Basics

Mechanical gages are familiar and economical. Air gages offer non-contact measurement and ease of use.

Inspection and Measurement 28 Apr 1998

When Indicators Go Both Ways

Measuring and gaging are two fairly distinct forms of dimensional inspection. Measuring is a direct-reading process, in which the instrument incorporates a continuous scale of units, against which the part is compared directly.

Inspection and Measurement 1 Mar 1998

Look Into My Stylii: Care Of Surface Finish Contacts

Proper care of contact points is one of the basic considerations in gaging. Whether you're using a simple indicator gage or a sophisticated surface finish instrument, much depends on the condition of the sensitive contact point, which is the interface between the gage and the workpiece.

Measurement 5 Feb 1998

Gaging Distance Between Hole Centers

Many of the gaging applications we've considered over the years involve size inspection of a single feature, that is, the diameter of a hole, depth of a groove, height of a gage block, and so on. Many parts, however, contain multiple features that establish dimensional relationships between two or more other parts.

Measurement 3 Jan 1998