How to Determine the Concentricity of Tubing
- 1). Lay the tubing flat on the cardboard. Slice downward with the razor blade or utility knife, and cut off the end to make it straight and clean. Once the end is clean, slice off a thin slice of tubing.
- 2). Measure the minimum and maximum wall thickness using the calipers. Place the two jaws of the calipers lightly against the inner and outer walls of the slice you have cut. Measure at several places around the disk you have cut to be sure of finding the minimum and maximum thickness. For purposes of illustration, assume you measured a minimum of 0.095 inches and a maximum of 0.110 inches.
- 3). Divide the minimum wall thickness by the maximum wall thickness. Multiply by 100 to get the concentricity in percent.
The concentricity for the example measurements would be 100 x 0.095/0.110 = 86.4 percent.
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