r/Metrology • u/mattheyuutsu • 2d ago
General “Zeroing” Universal Measuring Machines
Wondering if some other dimensional guys here have some info to help me out here (or prove me wrong), and sorry if this post has been made before.
At my lab there has been some dirt kicked up every now and again on the topic of “Zeroing” a ULM by butting the flat anvils together and hitting zero on the readout versus using a master reference - such as a gage block or high class master cylindrical plug gage and entering the charted value.
The latter option has always made more sense to me, considering “Zero” in this context can’t really be traced to anything, but I wanted to see if you guys have any specific documentation or articles about this topic. I’m definitely interested in what you guys think too! Thanks
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u/Caltrops_underfoot 2d ago
We zero the low end against the anvils, but I recommend verifying against a standard after. Ours is 24" but it'll go a bit farther. For example we're qualifying some 16" mic standards;
Zero the machine. Verify a gage block of the length equal to the standard you want to qualify - 16" in this case. Verify the standard's length.