Read all about the OFDA2000’s features and benefits.

Optical Fibre Diameter Analysis (OFDA) technology is used at all stages of the wool-processing pipeline, from greasy fleece through to yarn and fabric. It is also used to measure synthetic fibres, cashmere, mohair and alpaca.
The OFDA technology was developed by West Australian-based company BSC Electronics Pty Ltd - the inventors of the laboratory fibre-testing unit OFDA 100. Over 160 OFDA 100 instruments are in use in 22 countries throughout the world.
OFDA2000 is the robust, lightweight, fully portable extension of this technology and can be applied to general-purpose fibre measurement. OFDA2000 can provide rapid (25 seconds), accurate and precise diameter measurement along the length of greasy wool staples.
Fibres in greasy staples are coated with a varying thickness of grease, dirt and suint. The OFDA2000 automatically corrects for the grease factor, utilising a formula established after exhaustive analysis of Australian and New Zealand flocks. However, because average grease levels vary slightly from flock to flock, IWG recommends that users take advantage of the sonic scour that comes with the OFDA2000. Scouring a pre-determined number of samples from randomly selected animals in each mob will allow the establishment of a grease correction factor (GCF) that is tailored to the individual mobs, at the commencement of testing.


Example of along staple profile

The greasy wool measurements provided in real time by the OFDA2000 include:

• Mean fibre diameter (including a distribution histogram).
• Co-efficient of Variation of Diameter.
• Percentage of fibres less than 30 micron (comfort factor).
• Percentage of fibres less than 15 micron.
• Curvature and Standard Deviation of Curvature.
• Along staple diameter profile.
• Staple length.
• Position of finest and broadest points along the staple.
• Average of mean fibre ends.

Continuing research will extend the range of measurements and their applications.

Understanding OFDA
Much confusion exists throughout the industry about the perceived and actual differences in performance, accuracy and role of wool measurement equipment.
Our research suggests that most producers rank the portability, durability and ease and speed of operation of the OFDA2000, as superior to that of other in-shed testing equipment.
However, these advantages would be quickly removed, if OFDA2000 could not demonstrate clearly and unequivocally that it meets the highest possible standards in accuracy and reliability.

IWG is committed to achieving and maintaining world best-practise wool testing measurement standards that are demanded by all levels of the wool industry. Because significant differences exist between the sampling methods used in the OFDA2000 system and the core-test system applied when obtaining certified pre-sale wool tests, it was necessary for IWG to establish and prove beyond doubt that there is a high correlation between the results achieved under both circumstances.

To help demonstrate this, IWG commissioned SGS Wool Testing Services (one of the world's fore-most measurement surveillance and quality assurance companies), to undertake thorough evaluation of in-shed testing systems and the associated technology.
The evaluation demonstrated that there is a high correlation between the results achieved using OFDA2000 sampling method and the sampling method that is used in the alternative in-shed system.

The OFDA2000 test is conducted on sub-staples selected from a representative wool sample taken from a consistent site on the fleece, whilst the alternative in-shed testing system uses mini-cores from a skirted fleece. SGS explains a trial process that was conducted to compare the two systems in April 2000 and comments on the findings:

Duplicate hand samples were taken from the pinbone and midside sites on 33 Merino fleeces that had been individually packed in polythene bags after shearing. From these samples, staples were taken for measurement on the OFDA2000. The samples were subsequently sent to a laboratory for measurement on another OFDA2000 instrument under standard conditions. After heavy skirting, the fleeces were minicored twice using the FleeceScan system. Each set of minicore snippets, after solvent washing in the FleeceScan washer, was then measured by both the Laserscan and by another OFDA2000 operating in OFDA 100 mode (i.e. using snippets on a standard OFDA slide). The skirted fleeces were hand cored, and the cores measured offsite on an OFDA 100 after blending, minicoring and solvent scouring and drying.

The mean fibre diameter results are summarised in table 1 and show excellent correlation between the systems. The pinbone and midside sites gave very similar results in this case (although this should not be expected in general), and the on-site and off-site OFDA2000 measurements (on separate instruments) were also similar. Both the Laserscan and OFDA100 results on the washed minicore snippets were in this case broader on average than the OFDA2000 results on the greasy samples, and the OFDA 100 results on the core samples. In this trial, the precision of the OFDA2000 measurements was similar to the precision of the FleeceScan system. Both systems were judged equally capable of being used to objectively sort fleeces for mean fibre diameter.*
This independent process and assessment has provided IWG with the confirmation it needed and demonstrated that the OFDA2000 advantages of portability and durability, when combined with industry standard accuracy and repeatability, places OFDA2000 technology at the head of its field.
Research papers include:

1. PRECISION OF MEASUREMENT OF DIAMETER, AND DIAMETER-LENGTH PROFILE, OF GREASY WOOL STAPLES ON-FARM, USING THE OFDA2000 INSTRUMENT. -- B.P. Baxter
2. THE INFLUENCE OF DATE OF SHEARING ON THE PROCESSING PERFORMANCE TO TOP OF MINI-COMMERCIAL CONSIGNMENTS OF MERINO FLEECE WOOLS GROWN IN EITHER SOUTH WESTERN OR EASTERN AUSTRALIA; IMPROVED PREDICTION FROM THE FD PROFILES OF STAPLES FROM COMPONENT SALE LOTS. -- Andrew D. Peterson and Chris M. Oldham

* Full copies of the reference papers will be available shortly, through the Research Papers button at left.


Uses
OFDA2000 has a range of applications for woolgrowers to use in the yards or wool shed. In our experience, we find that each user will have a different set of priorities.

On farm applications includes:

• Culling for broad micron, coarse edge and other wool characteristics.
• Ranking and genetic selection.
• Preparation of wool for sale.
• Setting up sheep sale lines.
• Nutritional management practises (along staple micron profile management), for optimising micron and staple strength.

Below: OFDA2000 in operation at Bendigo Station, NZ, where it was used to test 17,000 fine wools at a throughput average of 1200 per day. In this instance, the skirted and rolled fleeces were placed on a conveyor wool table, which took the fleeces and skirtings past the OFDA2000 (samples were taken from mid-side) and then onto the classer. The wool was classed into half micron lines, with the finest line a "14s".