What is the Coefficient of Variation of Diameter?

Coefficient of Variation of Diameter (CVD) is a measure of the variation in micron measurements along and between individual fibres, relative to the average (or mean) fibre diameter. The CVD is calculated by dividing the Standard Deviation of Diameter (SD) by the Mean Fibre Diameter (MFD), then multiplying the result by 100 to express it as a percentage.

For example, a wool with a Mean Fibre Diameter of 20 microns and a Standard Deviation of 4 microns will have a Coefficient of Variation of:

[(4/20) x 100] = 20%.

The reason CVD is calculated is that it allows a comparison of the variability of samples that differ in fibre diameter. SD has a limited usefulness in this task as its value increases with increasing diameter. CVD values are relatively constant across the range of diameters.

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More about Fibre Diameter Variation