A British thermal unit (Btu) is a standard unit of energy that is used in the United States and sometimes in the U.K.
There is another defect in tires that can cause a vibration called loaded road force variance. The tires and pass a visual inspection, a radial and lateral runout test, be perfectly balanced, but still cause a vibration. This is due to the internal defects in the tire.
1 The vibration can become irksome after a while. 2  We know that prolonged exposure to vibration can weaken aircraft components. 3  The bolts have worked themselves free because of the vibrations.  The vibration of the lawn mower has made my hands tremble.