First - with any sonic tester you verify the readings by checking a spot(s) on the block you can also measure with a micrometer or caliper, so it’s actually very easy to see how accurate it is, our experience is these are really very close. Second - since I bought my tester I have randomly double checked a few blocks I have that I previously had professionally sonic tested before I owned it, all the spots I’ve tested have checked to within .000”-.003” of the readings from the professional shop, which I consider pretty good since although I know the approximate location the shop measured, it’s possible I’m measuring some spots in a slightly different location. Finally, I’m sure you saw in the other post, you’re not sanding across the thin metal strip in the center of the transducer. Just my experience, but the accuracy has been fine. I’m pretty sure a few others on the forum here have purchased these since this post, maybe they will chime in.
