It might be heath robinson but if it works then great.  You would probably need to manufacture something.  Maybe base it on some kind of dial gauge but with custom manufactured tip and mounting arrangement?

Or make up a series of tools with measured depth and use them like feeler gauges one at a time. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hey all,

I recently joined a composite company as a QA inspector. We make a lot of kevlar and carbon laminates. We have specs that require us to check surface pitting on these parts. The companies method for checking this has been by taping a paperclip to a 3d printed shim. They tape the clip so its offset to the maximum allowed value for pitting. Then they place the clip in the pit. If it doesn't touch the bottom, they call it OOT. If it does, its good to go. I feel like there's gotta be a better way to do this, not only to instill more confidence in the reading,  but to get an actual number out of it.

Does anyone have any recommendations for achieving such a task in a more sophisticated way? Keep in mind, most of the pits we are checking are usually within .200" in length and .100" height. I tried looking up some sort of needle depth gauge, but nothing really came of it. Any suggestions are appreciated!