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By Jeff Bibee

Optical measurement, when clearly understood and applied, can bring huge benefits. It can also be an investment disaster. To avoid the latter, we need to start with an understanding of the basics--the capabilities and limitations of optical measurement. Then, we can consider the applications where it might provide a better solution over current methods, such as touch probes, optical comparators, hand gauges, or microscopes. Digging deeper, we can discover the challenges that those applications present to optical measurement, the limitations, and the potentials for failure. In this article, we will investigate the optical tools and software strategies that have been developed to meet those challenges. With a deeper understanding, the right technology can be applied to the task, and the investment dollars will make sense.

The basics

The diagram in figure 1 below illustrates the basics of optical measurement: lighting, optics, XY Stage, and a Z axis that handles the focus.

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By Mario Perez-Wilson


The process potential index, or Cp, measures a process's potential capability, which is defined as the allowable spread over the actual spread. The allowable spread is the difference between the upper specification limit and the lower specification limit. The actual spread is determined from the process data collected and is calculated by multiplying six times the standard deviation, s. The standard deviation quantifies a process's variability. As the standard deviation increases in a process, the Cp decreases in value. As the standard deviation decreases (i.e., as the process becomes less variable), the Cp increases in value.

By convention, when a process has a Cp value less than 1.0, it is considered potentially incapable of meeting specification requirements. Conversely, when a process Cp is greater than or equal to 1.0, the process has the potential of being capable.

Ideally, the Cp should be as high as possible. The higher the Cp, the lower the variability with respect to the specification limits. In a process qualified as a Six Sigma process (i.e., one that allows plus or minus six standard deviations within the specifications limits), the Cp is greater than or equal to 2.0.

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By Dave K. Banerjea

If your company is involved in manufacturing, chances are that a good portion of your company's assets include measurement and test equipment (M&TE). This includes everything from simple go/no-go plug gauges to air-pressure gauges, voltmeters, micrometers and calipers on up to very sophisticated equipment such as robotic coordinate measurement machines and scanning electron microscopes.

 M&TE are those assets your company uses to make critical decisions on whether to pass or fail incoming materials, in-process work and finished goods.

 Of course, M&TE itself must be periodically inspected, tested and calibrated as part of the quality process. Poor or unreliable measurements result in faulty decisions and questionable product quality. Calibration management software can be crucial to helping maintain equipment accuracy and properly calibrated testing equipment.

 Calibration management software saves time, effort and money. Computerizing your calibration records makes them instantly available in the event of product quality problems or a quality system audit.

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By William H. Denney, Ph.D.

“We are going to win, and the industrial West is going to lose: There’s nothing much you can do about it because the reasons for your failure are within yourselves.”

--Konosuke Matsushita  

They work tirelessly to change our world irreversibly. If they succeed at what they’re doing and aren’t challenged, our way of life as we know it will end. While we whine about our bosses, our organizations, and our government; while we do the minimum that our jobs require; while we flip-flop through the mall and watch Oprah they’re planning, learning, and executing. When we’re tucked away in our beds, tossing and turning in restless sleep, they’re even busier. They don’t seem to tire; their passion is relentless. To them, weekends and holidays are inconsequential in their desire to have what we have.

We’re at war, but we seem oblivious to it. Our children’s future, our families, even our liberties are at risk, but for now, apathy is our primary defense. Secure in our ignorance of what’s happening far away, we think that we’re safe. But we’re not.

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By Charles Wells

Most in the electronic manufacturing services industry are acutely aware of the growing problem of counterfeit and substandard electronic components within the supply chain, as well as the headaches that they cause.

Although industry and governments are working diligently in addressing counterfeit abatement, you may already have one of the most useful tools in combating phony parts in place right on your production floor.

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By Chris Eckert

Manufacturers’ efforts to do more with less have resulted in purchasing departments sourcing cheaper products and parts, often from overseas. Such cost-cutting certainly makes purchasing look good to management. But the effect on quality professionals may be just the opposite: product or part defects, malfunctions or undesirable side effects, not to mention the challenge of producing high-quality end-products within narrow timelines and budgets. Many sleepless nights are a frequent outcome.

Because cost cutting and global sourcing are here to stay, how can quality professionals combat these monumental challenges? Root cause analysis (RCA), when fully utilized, can eliminate defects in your operations as well as defects that you inherit from suppliers, ultimately helping to maintain a satisfied and engaged customer base.

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By Terri D. Lind

Energy generation is a multifaceted industry comprising dozens of major discrete technologies and thousands of companies. For reasons that are at once political, economic, and environmental, the energy industry occupies a central place in modern human society, and it will for the foreseeable future.

Alternative energy resources, such as photovoltaic modules and wind turbines, represent a particularly fast-growing segment of the industry. This article will look at this sector from the perspective of quality assurance and safety testing, two extremely important concerns for producers, as well as consumers, of alternative energy.

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By Mark Ames

The last few years have provided ample evidence that control of food safety is critical. Recent media reports have clearly documented supply chain shortcomings that have threatened consumers’ health and safety. These ongoing problems and the need for consumer safety cry out for additional tools to dramatically reduce or eliminate risks.

Milestones in U.S. Food and Drug Law History

 

1883
Dr. Harvey W. Wiley becomes chief chemist for the U.S. Department of Agriculture. Campaigning for a federal law, Dr. Wiley is called the “Crusading Chemist” and “Father of the Pure Food and Drug Act.”

 

1906
The original Pure Food and Drug Act is passed by Congress on June 30 and signed by President Theodore Roosevelt. The Meat Inspection Act is passed the same day.

 

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By William A. Stimson, Ph.D.


One of the most important objectives of an internal quality audit is measuring the effectiveness of an organization's quality management system. For this to happen, executive management must first meet its overriding responsibility of establishing and maintaining a system regarding quality policy, goals, resources, processes and effective performance--including monitoring and measuring the system's effectiveness and efficiency.

ISO 9001:2000 delineates this responsibility into three distinct areas: 4.1 General requirements, 4.2 Documentation requirements and 4.3 Quality management principles. If an organization's executive management isn't active in these three areas, then they won't be addressed and the quality system will be ineffective. Let's look at them one at a time, first in terms of their meaning and then as auditable characteristics.

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By Rich Burnham

During the 1920s, a British statistician named Ronald Fisher put the finishing touches on a method for making breakthrough discoveries. Some 70 years later, Fisher's method, now known as design of experiments, has become a powerful software tool for engineers and researchers.

But why did it take engineers so long to begin using DOE for innovative problem solving? After all, they were ignoring a technique that would have produced successes similar to the following modern-day examples:

• John Deere Engine Works in Waterloo, Iowa, uses DOE software to improve the adhesion of its highly identifiable green paint onto aluminum. In the process, the company has discovered how to eliminate an expensive chromate-conversion procedure. Savings: $500,000 annually.

• Eastman Kodak in Rochester, New York, learns via DOE software that it needs only to retool an existing machine instead of making a huge capital purchase for a new one. The solution means improved, light-sealing film-pack clips used by professional photographers. Savings: Setup time drops from eight hours to 20 minutes; scrap reduces by a factor of 10, repeatability increases to 100 percent and $200,000 is not spent on a new machine.