Spinner Bearing Tube Tester Wilmad's Spinner Bearing Tube Tester is easy to use. Just insert and snap your fingers to test each tube. No matter how good Wilmad's NMR tube was when you got it, under those conditions, seriously warped NMR tubes will be created. Have everyone read Wilmad's Resonance Report NMR-010. Also have every tube pass the spinner bearing test before it goes into your spectrometer.
Warped tubes bind in the spinner bearing, good tubes spin freely.
It could be the best investment you ever made. Resonance Report NMR-010 describes tube quality and how it affects your spectrometer.