The Measures of Fiber Length
1. Mean Length: Numerical Average length of fibres of given population of fibre.
2. Upper Quartile: Length for which 75% of all observed values are lower or 25% higher by weight or number
3. Modal Length: The most frequently occuring length of fiber.
4. Median Length: Length Below and above which 50% of fibres lie.
5. Half Fall Value: The fiber length higher than modal length having half the modal frequency by wt. (Group length longer than mode with frequency equal to 1/2 of mode.)
6. Effective Length: Upper quartile of numerical length distribution from which some of the shortest fibers, having length less than half of effective length are cutailed or eliminated.
7. short fiber %: It is the % of fibers having length less than 1/2 of the effective length value.
8. Uniformity Ratio: Ratio of 50% span length to 2.5 % span length.
9. Span Length: It is the distance that can be spanned by specified percentage of fibers in a test beard.
10. Irregularity: Percentage by weight fo fibers in a sample which are shorter than 3/4th of the mode.
11. Dispersion %: inter quartile range expressed as % of effective length.