All Features
Belinda Jones
The Certification Committee of the Coordinate Metrology Society (CMS) has been laser-locked on its target to deliver its first Level Two Certification, a device-specific performance assessment for users of portable coordinate measuring machines (CMMs). Those efforts will come to fruition at this…
Ron Hicks
With the 30th anniversary of the Coordinate Metrology Systems Conference (CMSC) around the corner, I am happy to celebrate World Metrology Week with you. This year’s conference will be held in North Charleston, South Carolina, from July 21–25, 2014. Charleston is the oldest and second-largest city…
Laser trackers and the software that controls them have revolutionized the way metrology data have been taken. With software and hardware advances have come new and better ways to take measurements. One of these advances in metrology software is the ability to measure the angle normal to a mirrored…
NIST
Microscopes don’t exactly lie, but their limitations affect the truths they can tell. For example, scanning electron microscopes simply can’t see materials that don’t conduct electricity very well, and their high energies can actually damage some types of samples.
In an effort to extract a little…
In 1927, my grandfather, A. N. Brunson, was 22 years old and repairing surveying instruments. That was the year he established Brunson Instrument Company in the back room of a map business in downtown Kansas City. When the Great Depression came along, he was fortunate to keep very busy. Because no…
Belinda Jones
M
etrologists employ numerous portable 3D metrology devices and techniques to acquire coordinate data to measure a manufactured article or assembly. There are many variables induced by an operator that can dramatically influence data collection. Although measurement equipment is calibrated to…
U.S. Air Force
The 2nd Maintenance Squadron’s Precision Measurement Equipment Laboratory (PMEL) at Barksdale Air Force Base in Bossier, Louisiana, calibrates and maintains an inventory of more than 6,700 pieces of equipment for Team Barksdale. With countless tools and test equipment used by ground crews every…
Automated Precision Inc.
Hexapods: The word sounds alien, but we see them every day. A hexapod (“hexa” is the Greek word for six; “pod” is Greek for foot) is simply a spatial motion machine with six driving elements. They can be seen at fairgrounds, as the motor for carnival rides, or on flight simulators for pilot…
Taran March @ Quality Digest
“Measure what is measurable, and make measurable what is not so.”—Galileo Galilei
It’s all well and good to say that metrology “includes all theoretical and practical aspects of measurement,” but that doesn’t adequately express its gestalt, which I think even metrologists would agree is hard to…
Donald J. Wheeler
Who could ever be against having good measurements? Good measurements are like apple pie and motherhood. Since we all want good measurements, it sounds reasonable when people are told to check out the quality of their measurement system before doing an experiment or putting their data on a process…
Cathy Hayat
Air travel has long been considered the safest form of transportation. Statistically speaking, the average American is safer in an airplane than an automobile. Though this is reassuring, the industry is relentlessly pursuing ways to improve air travel safety. One such improvement is the continued…
Mike Richman
World Metrology Week is a good time to think about how the science of test and measurement affects our lives. From reducing the time and cost of large-volume manufacturing and assembly to helping ensure the safety and reliability of aircraft, automobiles, and sea vessels, portable coordinate…
Knowledge at Wharton
It used to be that restaurant goers who were impressed by a particularly attentive waiter or waitress could praise that person to the manager or leave a generous tip. This kind of transaction is still available in many places of business, but increasingly the feedback loop has become more tangled…
Dave K. Banerjea and Gary Phillips
MSA, the often-used abbreviation for measurement system analysis, refers to the use of analysis to predict the statistical properties of measurement systems. In the realm of calibration management, this analysis can apply to gauges and other measurement equipment, calibration procedures, or other…
MIT News
According to a 2013 United Nations report 2 to 5 percent of all international trade involves counterfeit goods. These illicit products—which include electronics, automotive and aircraft parts, pharmaceuticals, and food—can pose safety risks and cost governments and private companies hundreds of…
Nick O’Donohoe
Wayward and capricious, the wind has long been used as a metaphor for constant change. Wind turbine engineers deal with that changeability every day, along with a host of other challenging factors.
Turbines must operate in desert sandstorms and corrosive saltwater. The ambient temperature at the…
NIST
JILA researchers have engineered a short, flexible, reusable probe for the atomic force microscope (AFM) that enables state-of-the-art precision and stability in picoscale force measurements. Shorter, softer, and more agile than standard and recently enhanced AFM probes, the JILA tips will benefit…
Dave K. Banerjea
Story update 4/24/2014: We bumped up the cost of accreditation based on comments that the original article was on the low side. We also added references to ILAC as well as additional accreditation bodies that operate in the United States (ACLASS, NVLAP, L.A.B.)
Getting calibration accreditation is…
TE Connectivity
For more than 50 years, the linear variable differential transformer (LVDT) position sensor has been a reliable tool for linear position feedback for laboratory, industrial, military, and aerospace applications. These sensors can provide linear displacement measurements ranging from microinches…
Bruno Scibilia
My main objective is to encourage greater use of statistical techniques in the service sector and present new ways to implement them.
In a previous blog, I presented an approach you can use to identify process steps that may be improved in the service sector (quartile analysis). here I’ll show…
Joel Smith
In part 1 and part 2 of this series, we looked at the numbers of parts, operators, and replicates used in a gauge repeatability and reproducibility (GR&R) study and how accurately we could estimate %Contribution based on the choice for each. In doing so, I wanted to provide you with valuable…
Dave K. Banerjea
Calibrating measurement and test equipment (M&TE) is expensive, but using equipment that is out of calibration can be even more costly. Faulty M&TE will produce suspect parts, and once you've discovered that your M&TE is the problem, you’ll have to screen the suspect parts and repair…
Joel Smith
In part one of this series, I looked at how adequate a sampling of 10 parts is for a gauge repeatability and reproducibility (GR&R) study and provided some advice based on the results.
Now I want to turn my attention to the other two factors in the standard gage (or gauge, if you prefer)…
Joel Smith
You take 10 parts and have three operators measure each part two times. This standard approach to a gauge (or gage, if you prefer) repeatability and reproducibility (GR&R) experiment is so common, so accepted, so ubiquitous that few people ever question whether it is effective.
Obviously one…
John Palmateer
This article estimates the uncertainty for measuring a tool tip using dual Leica T-Mac sensors set up on opposite sides of an NC machine head and measured with tracking interferometers at opposite ends of a machine bed. Performance testing compares the estimated and measured uncertainties and…
