Sonic checkers

Thanks for the input. I'm still learning how to use one but not going to give up yet. I figure that if I have 6-7 pieces of different thicknesses of cylinder walls then I should be able to get it calibrated right. The very expensive tester that I was using was from work. On even has a tv screen that shows a graph with the peaks and I don't pretend to know how that works. The others were not as expense but get sent out to get certified every year. The one I'm using is now mine own that I bought for cheap. The readings were very steady but it's not calibrated to cylinder bores. I will calibrate it using the velocity...moving it up or down until I get it reading right then try a few more pieces and see if it's reading right. It only reads correct from 0-50c so that stinks but what can you do. If it all works I think it will be a great tool and save me alot of money and run around time checking up to 10 blocks before I get want I want. Thanks again for you input.