Originally Posted by
etherhuffer
Look on eBay for "dental calipers" Small and inexpensive and will measure down to .1mm so you can check thickness of rim wall.
Also known as a "Crown Thickness Gauge". Some really cheap ones may not be very good. The one you linked to looks decent.
I think I paid about $60 for the one I was required to buy in dental school. It's made in Germany, and very nicely made. I still use it... but I wouldn't spend that much on it again!