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Bench Talk for Design Engineers | The Official Blog of Mouser Electronics

Harsh Environments: Governed by Murphy's Law Arden Henderson


What is a harsh environment? It might be a holiday dinner with the polar-opposite-political relatives, especially if later trapped in the living room by a crackling fireplace with the distant uncle who sends four chain emails a day. But, today we're talking about harsh environments for electronics. Electronics Hell.

What is it like in Electronics Hell? There will be extreme heat. Or extreme cold. Vibration. Particle bombardment. Mind-blowing hi-voltage electricity in all the wrong places. Contamination by dust or fluids.
Radiation. Melting. Electrons running screaming from the room. Parts being shaken apart. Connections corroded beyond all hope. Static electricity snapping and rendering parts instantly non-functional. Fire and brimstone spiraling out of control. "Dogs and cats living together! Mass hysteria!" [Venkman]

Space comes to mind as a harsh environment. "In space, no one can hear electronics scream," as noted by Warren Miller.[1] The final frontier is really harsh for humans and for electronics. Extreme temperatures on either end plus near vacuum. A pleasant place, indeed. There is the additional problem of high-energy particles flipping bits all over the place in electronic memory. Unlike in Hollywood sci-fi movies where everything comes out right in the end, well, except for maybe Event Horizon (1997), electronics will die a horrible death if parts are not properly specified for space's harsh environment. Electronics failure in space might mean a zillion-dollar satellite is now orbiting, dark junk. Or, it could mean the lives of humans.

For example, your basic random particles are one problem. The other?
Space aliens. Probably not friendly. (Well, no friendlier than your typical singularity popping up, AI suddenly become self-aware.) Imagine, if you will, a deep space Blienstine Principle-powered alien ship (somewhere from Quadrant 1.4502.1) silently sidling up to the SpaceX-NASA-General-Motors YNM-150 Mars convention-powered spaceship, trundling half-way to its objective. Yeah, wormholes and whatnot. First thing they do? Hack the ship. Blow the oxygen tank valves. Someone didn't properly shield the ship's computers. It's all about the spec.

Speaking of shields, enclosures are important. Dust. Fluids. Particle bombardment. Fortunately, there are well-established guidelines. For example, the IP (Ingress Protection) code under the IE 60529 standard from the International Electrotechnical Commission (IEC) [2] [3] [4], and the National Electrical Manufacturers Association ( NEMA) ratings [5] [6], all of which establish standards of protective enclosures in context of  harsh environments. The MIL-STD-202 Test Method Standard [7] [8] covers a hosts of bad things that can happen to electronic parts, including vibration, shock, acceleration, and heat.

Let's talk about shock. Say you are specifying the electronics in a new law enforcement robot for your company. The mechanical engineers have already specified adequate armor. Nonetheless, the electronics must be specified to stand the shock and vibration, especially important if M855 rounds start flying in. It could mean the difference between accomplishing the mission and saving law enforcement lives.

So, all said, what makes up a harsh environment? The range is wide. From deep drilling operations to space flight, operating conditions will be tough. Vibrations, intense heat or cold, contamination by particulates, and a host of electrical dangers lurk just around the corner, such as electromagnetic interference (EMI) and electrostatic discharge (ESD).
Simple shock from impact can kill parts. All of these things must be understood going into the design process. All the things that can go wrong actually going wrong. Murphy's Law reigns.

Browsing to the Mouser Electronics website, we see it is chock-full of cool, informative articles on harsh environment applications plus links to related products and more. Mouser's harsh environment launch page, which includes links to technology, featured products, articles, and technical sources starts here.[9]

Cool Mouser articles about harsh environments include extreme conditions hazards by Greg Quirk [10], notes on purchasing products for harsh environments by Blair K. Haas [11], a lightning protection article by RFM [12], the vibration protection essay by David Askew [13], notes on power by Michael Parks [14], and complex sensing and control systems in harsh environments by Warren Miller [15]. Mouser also has automotive application articles such as Lynnette Reese's "Telemetry in Auto Racing" article [16], and "Inertial Measuring has Come a Long Way" by Tommi Vilenius [17]. 

Speaking of sensors in telemetry in race cars, let's talk about vehicles driven on the daily commute, more or less at the same speeds as race cars. Like everything else that goes into an automobile, pickup truck, SUV, motorcycle, and all vehicles in-between, electronic parts must be specified for harsh environments. For example, the heat inside a parked car can bake everything inside it to hellish degrees but the electronics are expected to turn on and start working perfectly.
Automotive electronics must live and still perform even if they have been cooking for hours at, say, 13,000 degrees Centigrade for hours in a parking lot in Phoenix, Arizona. It's expected we can hop in the car, turn on the A/C, cool down as we cruise out, joining the daily NASCAR-style commute to home and work.

Everything must work and all of the automotive electronics must survive the harsh environment under the hood and in the formerly baked interior with nary a peep or whine. Or, freezing temps while the car sits in the snow-driven parking lot or grinds through wind, ice, snow, past annoyed abominable snowmen. There's the vibration. Speed bumps, pot holes deep enough to swallow small recreational vehicles, tailgaters snuggling right up next to the rear bumper, occasionally tapping the vehicle NASCAR-style. Solder joints have to hold and shrug it all off, the shock and vibration. Connectors must not fail. Circuit boards must not crack and burst into flames. Extremes.

Everywhere you go on the Mouser site for harsh environment information, applications, technology notes, and product selections, there are plenty of handy cross-reference links, making proper choice of product straightforward, consistent, and predictable. The development kits rock, by the way.

Whether in space, deep under water, under the hood of a racing car or the family SUV, deep in a drilling operation, or the countless other harsh environments, both hazardous and non-hazardous, stuff must work.
Even in mildly harsh environments where, say, a drenching can happen, like getting caught in a downpour with your cell phone and no umbrella.
Designing for harsh environments takes a careful approach, lots of research, lining out all of the "what if" scenarios, and correct product specifications for harsh environments. All of which ensure the longevity and dependability of electronics that makes our world what it is today, saving lives, delivering the goods, and getting folks from here to there, especially on Mars.

A better world is built where electronic parts never fail catastrophically in harsh environments, electrons running screaming from the room.



















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Arden Henderson spent at least part of his life toolsmithing in dark, steam-powered workshops of software tool forges long gone, drenched in blood, sweat, and code under the glare of cathode ray tubes, striving for the perfect line of self-modifying software and the holy grail of all things codecraft: The perfectly rendered pixel. These days, when not working on his 1964 Flux Blend time machine (which he inadvertently wrecked before it was built after a particularly deep recursive loop), Mr. Henderson works in part-time castle elf and groundskeeper jobs, chatting with singularities spawned from code gone mad in vast labyrinths of vacuum tubes, patch cords, and electro-mechanical relays. Mr. Henderson earned a B.S.C.S. late in life at Texas A&M. Over the hundreds of years gone by before then and after, he has worked in various realms ranging from petrochemical wonderlands spread across the flat Gulf Coast saltgrass plains, as far as the eye can see, to silicon bastions deep in the heart of Central Texas.

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