Brunson Instrument Company

A Blog for Metrology Enthusiasts

The Pharaohs Were a Bit Short-Sighted

The Egyptian pyramids have stood for millennia, but they could have been stronger.

The Egyptian Pyramids at Giza.
Source: KennyOMG via Wikimedia

Yes, even after enduring 5,000 years of sandstorms and erosion the Pyramids at Giza still stand tall and proud… but they could have been built even better. Instead of four sides, Egyptian engineers could have used a tetrahedron--a three-sided pyramid on a triangular base.

The stability of a tetrahedron would have made the pyramids even more durable… and maybe even useful. Think of the metrology applications of using that solid structure as a base!

Four triangles make the sturdy tetrahedron.Brunson's engineers considered the tetrahedron's inherent strength when they developed the patented TetraLock® portable metrology stand. A tetrahedron gets its stability from the perfect frame of a triangle - the only rigid polygon. Put four triangles together and you have a sturdy tetrahedron.

With minimum play, the TetraLock portable stand supports laser trackers, articulating arms, laser projectors, scanners, total stations, theodolites, and more, steadily holding instruments up to 125 lbs (56.7 kg). Users' CMM readings are consistent and reliable when mounted on this sturdy workhorse.


Designed to be light weight but strong and easily portable, the TetraLock features collapsible legs. Historically, this has been a weakness of portable metrology stands. The mobility of the joints adds unwanted play to a structure that, in metrology applications, requires maximum stability.

But you still need those pesky mobile joints if your tetrahedron is collapsible. 

Brunson engineers cleverly utilized spherical connectors that lock the cross braces into the legs creating a positive stop. The stress induced by the internal force of the braces wrings out all play in the joints.

Once they're locked into place, the TetraLock stand has no plane of instability, and this key feature is a core element of the TetraLock patent. And with positive stop connections, play in the TetraLock is reduced to just one variable: material performance. 

Learn more about TetraLock here.To learn more about the great Pyramids of Giza, despite the design flaw (!), go here:

Source: MesserWoland via Wikimedia

Mark Meuret
By Mark Meuret on May 23, 2019 12:02:48 PM

Topics: Metrology, TetraLock, stand

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The Brunson blog is designed to be a platform for collaborative exploration in the field of metrology. You can expect to explore new Brunson products, hear from industry professionals invited to be contributing editors, and gain insight from customers who use Brunson products. So if you are one of the chosen few people who understand that Metrology is not a study of the weather, please join us here.