HALT…The Quest for Reliability


It’s a given that everything man-made can potentially fail at some point during its useful lifetime.  Designers and users of equipment would very much like to predict how long something is likely to last, how frequently failures can be expected, and what application conditions can lead to excessive failure rates.

One traditional measure of reliability is MTTF or Mean Time To Failure.  In the case of electronics, it’s a calculated number based on the failure rates of individual electronic components that make up the complete assembly.

There’s a growing trend toward determining reliability through physical testing.   One such method is called HALT or Highly Accelerated Life Test.  The goal of HALT is to subject electronic products to extreme conditions that will induce premature aging and stress to uncover weaknesses in the design or components.  These weaknesses can then be designed out of the product during product development, before they ever reach the end-user application.

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Add Value with Smart Linear Position Sensors


Way back when (in the sensor world, “way back when” = about 10 years), linear position sensors had to do only one thing: provide linear position feedback.  But these days, merely sensing linear position is not always enough.  In order to meet the needs of increasingly sophisticated applications, linear position sensors sometimes need to be able to provide advanced functionality.  Listed below are just a few of the advanced features that some of today’s linear position sensors offer.

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Automatic Size Change on a Budget – Part 2


In last month’s discussion “Automatic Size Change on a Budget – Part I”, we talked about the designer’s dilemma: accomplish size change at low-cost with an unsophisticated manual size change mechanism, or achieve high-performance automatic size change using costly servo drives.  This month we will look at some alternatives that nicely bridge the gap between affordability and automatic (or, semi-automatic) operation.

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Intrinsically Safe Vs. Explosion Proof


Industrial sensors are often called upon to be used in so-called “hazardous locations”.  A hazardous area is one where flammable gases and/or dusts are either present, or could potentially be present.

Typically, sensors used in such areas must be specifically approved and certified for use in these areas in order to prevent accidental ignition of any flammable gases or dusts that may be present.  The two most common protection methods are referred to as 1) explosion proof, and 2) intrinsically safe.

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Hit Me With Your Best Shot: Sensors Must Withstand Punishing Applications


In today’s competitive manufacturing environment, the name of the game is increased throughput.  Unprecedented global competition means that industrial manufacturing machinery must be able to run better (faster, longer, hotter, etc.) and more reliably than ever before.

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Analog Signals: 0 to 10V Vs. 4-20 mA


In the world of linear position sensors, analog reigns supreme.  Sure there are all kinds of other sensor interface types available; digital start/stop, synchronous serial interface, various flavors of fieldbus, and so on.  But linear position sensors with analog outputs still account for probably two-thirds of all linear position sensors sold.

When choosing an analog-output position sensor, your choice generally comes down to analog voltage (e.g., 0 to 10 V), or analog current (e.g., 4 to 20 mA).  So which should you choose?

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