Acceptable Probe Sigma values

[[To...]]

What sigma value should the probe have to ensure its measuring accuracy?  I have heard .001 is ok but also heard .0002 is what it should be at or under.

[[Jo...]]

Where im at we aim for .0015 mm or lower, but ive heard many different answers to that question.

Edited June 16, 2025

[[To...]]

add "/25.4" to the formula

 

EDIT  someone edited their post...lol

Edited June 16, 2025

[[Ha...]]

At Zeiss, our recommendation for the limiting value is anything under 0.001 mm for VAST XT and VAST XXT sensors. One major exception are probes that are qualified in RC-CAA mode for VAST XXT sensors, where the sigma values typically range between 0.002 mm - 0.020 mm.

[[Ke...]]

New probes are typically below 0.001mm (I usually see 0.0003-0.0005mm). I definitely inspect probes when the sigma increases (0.001mm or higher); although it is best practice to visually inspect probes more often, regarless of the recorded sigma values.