Strategy for setting gauge

[[Ro...]]

Hey Guys,

we've got a new highly percise setting gauge to check our CMM with.
We regularly check the roundness of parts with a tolerance of <5µm up to 2µm (or 0,0002-0,0001" for the american guys here 😃 ).
I wanted the ring to varify that my CMM (Prisma Ultra) is capable of measuring roundness with this percision.
We do have better equipment to measure roundness with, but i want to keep it in the CMM to save time.

When the ring arrived i was hella excited to measure that thing until i read on the certificate how the diameter is measured.
I attached the part of the certificate which i dont understand. Can you guys tell me what the strategy is?
I can remotely understand the upper unmarked text, but the marked stuff is just weird to me.

[[No...]]

Did you order that thing in China? 😱
Or is this just where the translator comes from?
Oh wait - thinking about it, it sounds very German 🤣

I may be completely wrong, but this is what sprang to my mind while reading it:

[[Ro...]]

Hi Norbert,

Im Anhang hast du mal die deutsche Erklärung, da ist zumindest besser verständlich als diese schandhafte Übersetzung. Es steht halt nirgends wie groß die Kreissegmente sind? Und was ist jetzt der Maßgebende Durchmesser? Der Abstand zwischen den Schnittpunkten der Geraden oder der Abstand zwischen den Schnittpunkten der Kreissegmente?

[[Ow...]]

My Accura II roundness certification at calibration.
Notice they use a bigger probe (12mm) to certify roundness with. 🙄