Reference spheres : how it's made ??

[[Gu...]]

Hello,

I'm just curious about the reference spheres : how it's made ?!?!
I asked lots of people about this, nobody answered me !!!
I'm curious how to manufacture parts with small form error like these.
Maybe polishing ?

If anyone know about it 🙂


Thanks

Guillaume

[[Ja...]]

I asked the same question to one of the Zeiss calibration techs when he was in last year and he started telling me that all of the reference spheres are made by one old man in Germany with some secret tools of the trade and his apprentice. And when this old guy finally retires the reference sphere supply could dry up.

I think he was joking, at least a little, but he said it with such a straight face and then didn't elaborate further.

My guess is aliens.

[img]https://encrypted-tbn0.gstatic.com/imag ... VFLkEYRQ&s[/img]

[[Ya...]]

Hello my dearest conspiracy theorists,
here is my idea.

Some time ago I saw this Youtube video: https://youtu.be/ZMByI4s-D-Y?feature=shared

Have a nice day.

YM

[[No...]]

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He's right! Well, the apprentice is very young and still has a lot to learn. But look how talented he is!
In a few years he'll be able to chisel a 30 mm reference sphere that is just as beautiful as these practice pieces.

[[Gu...]]

Aaaaah you are all more inventive than each other 😃 😃 😃
Maybe it's one of the greatest mysteries of metrology 😱

[[Ke...]]

It is surprisingly simple, Zeiss uses a carefully crossbred strand of eggplant which grow perfectly spherical, and their expert horticulturists nurture them and pluck them at the appropriate size (different reference spheres are simply different growth times), at which point they are carefully cleaned then soaked in a permeating mineral solution to allow a process similar to petrification, creating beautiful ceramic spheres.
I kid of course, this manufacturing process is considered a trade secret and is not discussed outside the related teams.