George Schuetz Director of Precision Gages

22 Dec 2010

Making a Budget and Sticking to It

We have talked about the gaging process and evaluated it through various testing methods such as GR&R studies. We have also seen that there are other factors that influence gage performance, such as linearity, long-term stability and bias from the gage design. Combined, measuring-system-based factors that influence results are called the “measuring uncertainty.”

15 Nov 2010

What Do You Mean by Accuracy? (20 Years Later)

Nearly twenty years ago, I wrote the column “What Do You Mean by Accuracy?” Since then, new standards have been created or updated to reflect new developments and thinking about what accuracy is. So, has accuracy changed?

18 Oct 2010

Checking the Performance of Surface Finish Gages

The measurement of surface finish has come a long way in the past 60 years. We have advanced from fingernail scratch pads to microprocessor- and PC-based systems with inductive probes. We even have the choice of optical sensors to evaluate part surfaces.

20 Sep 2010

Gage Repeatability and Reproducibility Studies

GR&R studies are a way to assess the reliability of gaging results. For these studies, a few gage operators measure a small number of parts, several times each. The results are compiled and reduced to a single number that indicates the total expected spread of measurements for a single part, for all trials, by all operators. This number is expressed as a percentage of the total part tolerance.

18 Aug 2010

GR&R Studies: Measuring the Measurement

Over the last few columns we’ve been talking about measurement system analysis, or MSA. A key component of this overall analytical process is the GR&R study, officially known as ANOVA GR&R, or “Analysis of Variance Gage Repeatability and Reproducibility.”

19 Jul 2010

Measurement System Analysis: Using the Data

High-end transducers are available for precision dimensional measurement. These electronic systems can provide incredibly high resolution and accurate readings, but they are also able to transfer data to a data collection device, usually a computer.

16 Jun 2010

Electronic Gage Heads

Using probes to reduce uncertainty during the electronic gaging process.

13 May 2010

Measurement System Analysis

Range, resolution and accuracy in digital amplifiers and inductive probes.

15 Apr 2010

Dual Master Air Gaging Systems

Choosing a single master or dual master air gaging system can be difficult. Understanding the similarities and differences--in performance, price and philosophy--can help a user make the best choice for their application.

15 Mar 2010

Single Master Air Gaging Systems

Choosing a single master air gaging system can be difficult. Understanding the similarities and differences--in performance, price and philosophy--can help a user make the best choice for their application.

Basics 16 Feb 2010

How To Become A Master Of Deviation

In the June 2009 issue, I wrote about how “less” can be “more,” by purchasing lower-grade master rings and discs and using their certified size—their master deviation—to improve the gaging process accuracy. This topic sparked a number of questions and some confusion, primarily because I did not have space to talk about actually applying this technique on the shop floor.

Measurement 18 Jan 2010

Comparative Gages and Temperature Compensation

The use of electronic temperature compensation in gaging has become a valuable tool in improving accuracy as well as gage repeatability and reproducibility (GR&R) in harsh manufacturing environments.