GD&T Position

[[Ji...]]

Hello everyone,

We are frequently encountering measurement‑related questions. Many junior customers keep referring to various international standards such as ISO standards.

 

Our Calypso software has already been configured for ISO‑compliant evaluation.

I would like to clarify: when evaluating the position tolerance of a hole, is Gaussian (least‑squares) fitting the default method according to ISO requirements?

 

Which ISO standard and specific clause defines this rule?

[[Ma...]]

This is ISO compliant.

Datums are tangential, but measured feature is Gauss.

I think only difference about ASME and ISO will be in that feature's evaluation.

[[Ji...]]

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Sorry, I would like to know which part of the ISO standard defines this? I have searched for a long time but have not found any clear specification.

[[Ma...]]

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Hi and sorry, i have no document about this.

But years on forum and work on machines can give a clue how it is.
My main knowledge was with using ZEISS Inspect, where i can easily visually see how is ISO, ASME and GEOMETRY behaving.

Many hints were from

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 and his drawings and simulations.

[[Jo...]]

You can have a look here for the applicable standards.

https://dgq.de/fachbeitraege/iso-gps-matrix-modell/