| METR-300 |
Objective Measurement
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The subject of Wool Metrology covers all aspects of wool measurement or metrology and its effect on the marketing of Australian wool. It introduces the concept of objective measurement and explains in detail the procedures and measurements involved to objectively specify the Australian clip. The value of measurement to the industry is outlined. This subject is closely linked to the subjects Wool Technology and Wool Marketing and should supplement many topics introduced in the Wool Production subject. |
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The majority of Australian wool is objectively specified. All wools sold via the auction system have reported specifications of mean fibre diameter, yield and vegetable matter base, with most fleece and skirtings lots having the additional measurements of staple length and strength, position of break and in some cases colour. Topics within this theme deal with the theory of measurement and sampling, describe the routine measurements in detail, and explore issues of contamination and specification of carding wools.
You can download all presentations for each Topic as PPT presentations within a compressed archive (.ZIP) using the link provided for each Topic. You can preview the PPT presentation for each Module in PDF format using the link provided for each Module. The PDF does not include the notes.
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| METRO-300-050 |
Measurement Theory and Concepts |
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Modules in this topic address some basic measurement theory. Included is the theory behind good sampling procedures, an explanation of what fibre diameter is, the theory of the measurement of colour and an explanation of the measurement of Hauteur and CVH. |
| METR-300-050-100 |
Sampling Theory |
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Metrology comprises sampling and measurement. Generally, the aim is to obtain an estimation of the average value of a property within a population. This module addresses some basic theory which will aid the understanding of metrology. At the completion of this module you should understand the principles of sampling, the meaning of accuracy and precision, and how precision is calculated. |
| METR-300-050-200 |
What is fibre diameter |
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This module explains the importance of wool fibre diameter, and explores the difficulties in defining just what diameter means in terms of wool diameter measurement. |
| METR-300-050-300 |
Color measurement theory |
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This module is designed to introduce the concepts behind the measurement of colour. This work and the standardisation of colour measurement has been undertaken by an organisation called CIE (International Committee on Illumination), hence CIE Tristimulus Values, CIELAB etc. This organisation is still responsible for the standards associated with colour measurement, or colorimetry. |
| METR-300-050-400 |
The measurement of Hauteur (H) and CVH |
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This module defines Mean Fibre Length in the top and how this relates to Hauteur and Barbe. Measurement of average length of fibre in a top is covered. The significance of this measurement and other derived measurements such as coefficient of variation of Hauteur (CVH) in the spinning operation is also covered. |
| METRO-300-100 |
Raw Wool Sampling |
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The procedures and apparatus involved in the sampling of raw wool for objective measurement are described. |
| METR-300-100-100 |
Core Sampling |
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The objectives of this module is to explain the procedures and apparatus involved in core sampling. There are two (2) types of samples taken from bales: core samples and grab samples. CORE samples are taken for all measurements of characteristics which don’t require fibre or staple integrity to be maintained, such as Mean Fibre Diameter, Yield, Vegetable Matter Base (VMB) and Colour. GRAB samples must be taken where full length staples are needed, such as tests for Staple Length and Staple Strength and Style measurement. |
| METR-300-100-200 |
Grab Sampling |
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This module describes how a representative sample is obtained by grab sampling, and the instruments used to achieve this. There are two (2) types of samples taken from bales; core samples and grab samples. CORE samples are taken for all measurements of characteristics which don’t require fibre or staple integrity to be maintained such as Mean Fibre Diameter, Yield, Vegetable Matter Base and Colour. GRAB samples must be taken where full length staples are needed such as Staple Length and Staple Strength and Style measurement Individual sale lot grab samples are combined to form a display sample. This is displayed at the selling centre to enable wool buyers to assess the unmeasured characteristics of the wool. The sequence of wool sampling is as follows – grabbing, weighing, coring, tuft sampling and staple preparation. |
| METR-300-100-300 |
Staple Sampling |
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The wool sample obtained through Grab Sampling must be sampled further to obtain staples, which are representative of the sale lot. These staples are then used to objectively measure Staple Length and Staple Strength. This module follows on from Grab Sampling. |
| METRO-300-200 |
Determination of Wool Base and Yield |
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Within this topic regain and its measurement are explained, wool base and vegetable matter base defined and their application to the determination of yield parameters are outlined. |
| METR-300-200-100 |
Regain & Oven-dry Weight |
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The significance of regain and its measurement is described in this module. The use of oven-dry weight avoids the effect of the moisture content of wool during the determination of Wool Base (WB) and Vegetable Matter Base (VMB), which are then used in the derivation of Yield figures. |
| METR-300-200-300 |
Wool Base and Vegetable Base |
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This module is about the determination of Wool Base and Vegetable Matter Base. These figures are subsequently employed to determine the various Yield values used in the processing industry. |
| METR-300-200-400 |
Yield determination |
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This module is about the determination of Yield as applied to the trading and processing of wool, and the considerations inherent in this determination. This module has been aimed at understanding the reasons behind the formulae listed in the Standards. The questions being asked could be; How much fibre am I buying for my customer? How much fibre will I end up with at the end of my process? The determination of Yield depends on the derivation of figures for Wool Base (WB) and Vegetable Matter Base (VMB). For further information see the “Determination of Wool Base and VM Base” module. |
| METRO-300-300 |
The Measurement of Fibre Diameter |
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The major price-determining characteristic of raw wool is mean fibre diameter. This topic looks at standards for the measurement of fibre diameter and the components of variation of fibre diameter and its implication in the assembly of processing lots. |
| METR-300-300-100 |
Standards for fibre diameter measurement |
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This module examines the standards that are in place to measure fibre diameter, and looks at the role of standards in this operation. A “Standard” or “Test Method” lays down the regime to return a measurement which is accurate and has a known or quantifiable precision. This regime includes sampling, sample preparation, the number of measurements made and the instrument or instruments to be used. In other words when a diameter is quoted with the standard by which it was measured, the number given is put into a context. |
| METR-300-300-200 |
Components of variation of fibre diameter |
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This module describes how a representative sample is obtained by grab sampling, and the instruments used to achieve this. There are two (2) types of samples taken from bales; core samples and grab samples. CORE samples are taken for all measurements of characteristics which don’t require fibre or staple integrity to be maintained such as Mean Fibre Diameter, Yield, Vegetable Matter Base and Colour. GRAB samples must be taken where full length staples are needed such as Staple Length and Staple Strength and Style measurement Individual sale lot grab samples are combined to form a display sample. This is displayed at the selling centre to enable wool buyers to assess the unmeasured characteristics of the wool. The sequence of wool sampling is as follows – grabbing, weighing, coring, tuft sampling and staple preparation. |
| METRO-300-500 |
Additional Measurements |
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Procedures and instruments used in the additional measurement (AM) of staple length and staple strength, and colour are outlined. Fibre curvature measurement is also introduced. |
| METR-300-500-100 |
Staple Length, Staple Strength |
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This module outlines the procedures and instruments used in the objective measurement of Staple Length (SL) and Staple Strength (SS). |
| METR-300-500-300 |
The measurement of wool colour |
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This module examines how wool colour is measured, the sources of yellowness in wool, and importantly how discolouration of clean wool can affect the final product, particularly during dyeing. |
| METR-300-500-400 |
Introducing: Fibre Curvature |
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This module is designed to introduce the concept of fibre curvature. Items such as the definition of curvature, the measurement of curvature and its importance to the wool industry are covered. |
| METRO-300-600 |
Raw Wool Contamination |
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Raw wool contamination and its impact on processing is addressed. Sources of contamination are investigated and schemes to reduce contamination both on the sheep and in the shed are examined. Procedures used to detect and/or measure contamination are also presented. |
| METR-300-600-100 |
Dark Fibre / Medullated Fibre |
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This module examines the sources of isolated fibre contamination (medullation and dark fibre), the procedures available to ameliorate their effects, and the effect they have on final products such as fabrics. |
| METR-300-600-200 |
Implication of Non-VM Contamination |
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This module examines the sources of non-VM contamination in raw wool, the effect of this contamination on handling and processing, and the prevention of this type of contamination. |
| METRO-300-700 |
Carding Wools |
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This topic examines the use of specification for carding wools. Carding wools are those destined for processing through the woollen system, such as lambs wool, crutchings and locks. The fibre length measurement “Length After Carding” (LAC) is introduced as a means of assessing the mean fibre length of clean carding wool. |
| METR-300-700-100 |
Specification of Australian Merino Carding Wools |
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This module covers the objective measurements available to carding wools, and sets out the need for further objective measurements of carding wool. Australian Merino carding wools are presently sold mainly based on subjective appraisal, however, there is an increasing trend to sell wool electronically and a push from some parts of the wool industry to go to Sale by Description. If all the Australian clip was to be sold this way then there would be a need to report objective measurements of greasy carding wools. The scoured/carbonised wool traders also require objective measurements for clean wool which is a major trading point in the woollen industry. |
| METR-300-700-200 |
Length After Carding measurement for Australian Carding Wools |
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This module explains a method, “Length After Carding” (LAC), for assessing the mean fibre length of clean wool after processing on the woollen system of yarn manufacture. The prediction or estimation of LAC using greasy wool specifications is also discussed. |