Wow
That’s all I’ve got.
Originally shared by Michael Verona
How do you measure the strength of things? Steel, maybe, or aluminum or carbon fiber or titanium – how do you determine how strong a given alloy or construction or form is? For something simple, like a soda can, you might test it’s compressive strength – it’s resistance to being crushed – by incrementally stacking weights atop it until the can collapses; for tensile strength – resistance to being pulled apart – perhaps you hang the can from a strong chain and, in turn, hang weights incrementally from the can until it tears. Write down the last weight you added, and you have new knowledge.
But what about strong things, really strong things? Anchor chain for giant Panamax vessels, armor plate for military tanks, or even high-strength steel used in the construction of cars are going to need a lot of force if you want test them to failure.
The answer is not terribly complicated: you just use more weight, a lot more.
“_Inside a lab near Washington, D.C., there is a stack of stainless steel that weighs a million pounds.“
“_It’s part of a unique machine that was built in 1965 and just refurbished for the first time. And in the world of metrology, the science of measurement, this giant is a source of national pride.“
This is a simple – but very, very big – machine that measures compressive and tensile strength of materials, and can calibrate devices called force transducers that then can be used elsewhere to accurately measure forces applied in testing and development of materials.
NPR takes a brief look at the machine, and discusses how it was recently rebuilt using “_extra parts and special wrenches — the tools had been sitting around for half a century._” That conservation of tools and supplies is incredibly important because this massive machine is the only one in the world.
More detail and a link to a video here: http://www.nist.gov/pml/div684/grp07/reconditioning-deadweight-machine.cfm
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