How to Measure the Inside Diameter of a Barrel or Tube

This video describes various tools and techniques to measure the inside diameter of a smooth bore barrel or tube. First inexpensive tools are used then more expensive tools offering greater accuracy, precision and repeatability are investigated. Tools used include a scale, divider, caliper, telescoping gauge, micrometer, gauge block and finally a 3 point Mitutoyo hole gauge. Statistical methods are also introduced including average, coefficient of variation and Windsor trimming. Finally, the philosophy of real world measurement and its limitations is touched upon.