Hello:

Can someone correct me please? The reference element for a micrometer is the spindle. For a CMM what is the reference element? Is it the reference that it is compared to during calibration?

Thanks for thinking for me.

Jen

Hello:

Can someone correct me please? The reference element for a micrometer is the spindle. For a CMM what is the reference element? Is it the reference that it is compared to during calibration?

Thanks for thinking for me.

Jen

Your CMM should have a calibration sphere or a master part in which you run everyday. Also, your probes which do wear out are calibrated to the master sphere or part which will allow you to trend deviation from nominal.

I hope this helps direct you a bit further.

For a CMM what is the reference element? Is it the reference that it is compared to during calibration?

Would this (http://www.npl.co.uk/length/dmet/services/ms_stepgauges.html) help? Or this (http://www.ptb.de/de/org/5/53/texte/aspe.pdf) perhaps?

Stijloor.

Typically a cmm is referenced to a known volume described by a fixed, known length. Going off the top of my head, this is often known as the ANSI "Ball-bar" test. (I haven't looked it up, someone will, I'm sure).

My old company, Renishaw Metrology, made a device - the 'Machine Checking Gauge' (or it was called that) which comprises highly accurate and stable bar(s) of fixed length(s) which rotate about an accurate pivot point - used to check a volume in space. Your choice of arm length is dependent on the size of component you're normally checking on the cmm.

It's a nice bit of kit! (can I have my check now, Sir David?)

See what you can find out about these to see if they suit your application.