LORETTA's Progeny In Our Herd

05/11/2011 - Lulu

Out of Herd Progeny

No out of herd progeny on file

Definitions for Units of Measure in Fiber Stats Chart

Mean Fiber Diameter - This number, expressed in microns (µ), is the average diameter of fibers in the sample. One micron is equal to 1/1,000th of a millimeter. The smaller the micron count, the finer the fiber. MFD and AFD (average fiber diameter) are two terms that describe the same measurement.

Standard Deviation - SD represents an average of individual deviations (plus or minus micron values) from the mean or AFD. The smaller the Standard Deviation, the more uniform the population of fibers measured. It is the most stable of variability measures and is used in the computation of other fiber statistics such as the Coefficient of Variation (CV).

Coefficient of Variation of Fiber Diameter - CV (or CVD) is the Standard Deviation divided by the Average Fiber Diameter multipled by 100 and reported as a percentage. The CV is used in the statistical analysis of different populations of fiber (different animals).

Fibers > 30 Microns - This number is the percentage of fibers in the sample that measure more than 30 microns in diameter. When this number is subtracted from 100, the remainder is known as the "comfort factor." For example, five percent of fibers over 30 microns corresponds to a comfort factor of 95 percent.

Spin Fineness - This number, expressed in microns (µ), provides an estimate of the performance of the sample when it is spun into yarn. It is derived through a formula that combines the measured mean fiber diameter (MFD) with the measured coefficient of variation of fiber diameter (CVD). For a given MFD, a lower CVD will result in a lower spin fineness number, indicating an improvement in processing (spinning) performance. A 5 percent decrease in CVD is equivalent to a one micron decrease in MFD in its effect on spinning.

Mean Curvature - Fiber curvature is related to crimp. Mean Curvature is determined by the measurement of two millimeter (2mm) snippets in degrees per millimeter (deg/mm). The greater the number of degrees per millimeter, the tighter the crimp.

SD Curvature - Standard Deviation of Curvature means that 34 percent of the fibers measured are xx.xx degrees per millimeter (deg/mm) higher than the mean curvature and 34 percent are lower than the mean. Sixty-either percent of the measurement in a normal distribution lies within the first standard deviation. The lower the SD, the more consistent the sample is.

Comfort Factor - When the percentage of fibers in the sample that measure more than 30 microns in diameter is subtracted from 100, the remainder is known as the comfort factor. The higher the comfort factor of a given fiber sample, the fewer coarse fibers are present in that sample and the more comfortable that sample would feel against skin.