general questions


Fibre Diameter The mean (average) micron result of a sample.
SD Standard Deviation Measures in microns the spread of fibres either side of the mean FD in which 68% (two-thirds) of the fibres lie. The lower the SD the more uniform the wool.
CV Coefficient of Variation The CV is the SD divided by the mean FDx100. CV measures the FD variability as a percentage. CV tends to fall in the range of 15% to 30%, with 15% being very uniform wool, whilst 30% is highly variable wool.
%>30.5 Fibres greater than 30.5um Measures the percentage of fibres above 30.5 microns. Results greater than 5% may cause the pricklel effect.
CF Comfort Factor

Measures the percentage of fibres below 30.5 microns. Calculated as 100 minus the percentage of fibres below 30.5 microns.
SF Spinning Fineness Calculated using the mean FD and CV to determine an "effective" fineness. This figure gives a measure of spinning performance. For wools of any particular micron the spinning performance decreases as the CV increases.
CURV Curvature Measures how rapidly a fibre bends along an average standard short length of the fibre. Expressed as degrees of curve per millimetre of fibre (deg/mm). Curvature measurements usually range between 70 and 150 deg/mm. Curvature strongly relates to crimp frequency, therefore the higher the curvature the higher the crimp frequency.

Results for samples will normally be available between 5 to 10 days from receipt of samples.

Samples can be turn around in a shorter time frame by prior arrangement.

There is also a section on the 'test request form' which allows you to specify your preferred turnaround time for the return of your test results.

We are often asked which site is more appropriate to use - midside or pinbone. The site, in our opinion, is not as important as the manner in which you take the sample. It is necessary to take the sample from the same site with the same length of wool and mark the sample bag clearly.

Midside will give you the closest result to the average micron of the animal, although the pinbone is easier to take, in most cases it will give you a stronger result which is not correlated to the midside. Results from midside to pinbone may vary from zero to plus 2 microns.
Sampling size can also assist us. With micron only testing, we need roughly what you can squeeze into a coffee cup (or a 7oz glass). If you also require a yield test we require slightly more wool, about what you can squeeze into a coffee mug (or middy glass). We also prefer micron only testing to be in paper bags and yield samples in plastic bags. Riverina Wool Testers supply these bags at no charge, please email or ring for these sample bags to be posted to you.
To help improve sampling and testing times we have listed some items that are not required when using sample bags which can slow down sampling and testing procedures. We would appreciate that you do not use:
  • Knots
  • Sticky Tape
  • Staples
  • Rubber bands
  • Ties
  • Pencil when marking bags
By not using the above we hope to improve turnaround times and help keep test fees down. We also suggest that details on sample bags are clearly labelled with a permanent marker or by using barcode stickers provided by RWT.
By using Riverina Wool Testers sampling bags (which are provided free of charge), applying a simple fold to seal the bag ensures that each wool sample will not fall out and risk being lost.


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