A1.
Baxter, B.P., Brims, M.A. & Taylor, T.B.
Description and Performance of the Optical Fibre Diameter Analyser (OFDA),
IWTO, Nice, Dec 1991 (subsequently published in J. Text. Inst., V83, N4, pp507 - 526, 1992).
Describes the overall OFDA system and its development.
A2.
Baxter, B.P., Brims, M.A. & Taylor, T.B.
Further Studies on the Performance of the OFDA,
IWTO, Punta del Este, April 1992.
Details the results of experiments on OFDA to determine the effects of contamination, operator effects and snippet factors. The results of 1300 comparisons between OFDA and airflow are analysed.
A3.
Baxter, B.P.,
OFDA Round Trials with Greasy Wool Cores,
IWTO, Nice, Dec 1992.
Round trials are described involving 25 core samples of greasy wool, measured on 7 OFDAs in 4 countries. The results allow a more precise estimate of the variance components.
A4.
Baxter, B.P., Brims, M.A.,
Linearity and Focus Independence of the OFDA,
IWTO, Nice, Dec 1992.
Describes experimental work to verify the linearity of OFDA over a 5 to 125m range, and the independence of the result on focus within the normal focus range.
A5.
Baxter, B.P. & Teasdale, D.C.,
Suitability of the Interwoollabs IH tops for Calibration of the OFDA,
IWTO, Nice, Dec 1992.
Describes an investigation to determine whether the use of the Interwoollabs IH calibration tops adds significantly to the differences between OFDA instruments and laboratories. The results show the very small variations found do not add significantly to OFDA measurement variance.
A6.
Turpie, D.W.F., Steenkamp, C.H. & Lupke, E.E., Differences between Calibrations for Wool and Mohair on the FDA 200 and OFDA,
IWTO, Nice, Dec 1992.
Describes experimental work on the FDA200 and OFDA that provides evidence that different calibrations are required for wool and for mohair on both instruments.
A7.
Lupke, E.E., Wright, O.E. & Botes, A.C.,
Comparative study with OFDA and Airflow on Core Samples before and after Shirley Analyser,
IWTO, Nice, Dec 1992.
The OFDA was compared to the Airflow system on 408 core samples, with the OFDA samples being taken both before and after the Shirley Analyser procedure.
A8.
The Optical Fibre Diameter Analyser (OFDA) - New Technology for the Wool Industry,
B.P.Baxter, M.A.Brims & D.C.Teasdale,
Wool Technology & Sheep Breeding, Dec. 1992
A9.
Brims, M.A.,
The Theoretical Comparison of OFDA and FDA class Instruments for the Measurement of Fibre Diameter Distribution,
IWTO, Istanbul, May 1993.
Explains theoretical difference between the measurement of diameter at a point and by averaging over a circular beam, due to fibre curve. 10 Refs.
A10.
Brims, M.A.,
New OFDA Developments and the Use of the OFDA as a Projection Microscope,
IWTO, Istanbul, May 1993.
Provides an overview of use of OFDA as a manual projection microscope. 2 Refs.
A11.
Edmunds, A.R.,
Comparative Fibre Diameter Measurements on N.Z. Wools by Airflow, Laserscan and OFDA,
IWTO, Istanbul, May 1993.
The results of measurements between airflow, Laserscan and OFDA on 2 sets of New Zealand wools are graphed. The total number of samples involved is 140, ranging in diameter from 19um to 40um. 2 Refs.
A12.
Peterson, A.,
Development of the Optical Fibre Diameter Analyser to Measure the Fibre Diameter Profile of Single Wool Fibres,
Misc. publ. 2/94, Dept. Ag., W. Australia, Jan. 1994.
Describes initial results of a software module that allows the OFDA to scan single fibres mounted on a frame that replaces a normal slide. Fibres up to 55mm long may be scanned and a high resolution graph (7um along the fibre) of diameter is obtained.
A13.
Baxter, B.P.,
Review of the Suitability of the 1993 Series of Interwoollabs IH tops for Calibration of the OFDA,
IWTO Technical Report 14, New Delhi, Apr. 1994
Further to [A5], this paper confirms that the 1993 IH tops series is equally suitable for calibration of the OFDA.
A14.
Brims, M. and Peterson, A.,
Measuring Fibre Opacity and Medullation using OFDA - Theory and Experimental Results on Mohair,
IWTO, New Delhi, Apr. 1994.
Describes the optical principle used in the OFDA upgrade to measure fibre opacity and hence medullation of individual fibres. Includes graphs of fibre opacity for cashmere and mohair and a graph of medullation determined by manual projection microscope vs OFDA.
A15.
Baxter, B.P. & Brims M.A.,
1994 Round Trials on Sliver Samples,
IWTO, Nice Dec. 1994.
Reports the results of an international round trial carried out using OFDA and airflow on wool sliver samples. The precision of the OFDA was shown to be similar to airflow.
A16.
Baxter, B.P.,
Supplementary Analyses on OFDA Round Trials on Sliver Samples,
IWTO, Nice Dec. 1994.
A supplementary analysis of the above report to show that 2 slides per sample were adequate to achieve precision rather than the 4 slides used in the trial.
A17.
Baxter, B.P. & Brims M.A.,
1994 Round Trials on Greasy Wool Core Samples,
IWTO, Nice Dec. 1994.
Reports the results of an international round trial carried out using OFDA and airflow on greasy wool core samples. The precision of the OFDA was shown to be similar to airflow.
A18.
Brims M.A.,
Bias in Measured Standard Deviation that would result from Bias in Quoted Mean Diameter of Calibration Standards: Experimental Verification Using OFDA,
IWTO Harrogate, June 1995.
Using recent data from projection microscope (PM) round trials, the effect of short snippet lengths on PM and its subsequent effect on instruments such as OFDA is described. 11 Refs.
A19.
Edmunds, A. R.,
OFDA Measurements of Additional Fibre Parameters: Some Preliminary Results,
IWTO, Harrogate, June 1995.
Describes experimental results using the recent OFDA options for measuring medullation and snippet curvature. A good calibration was obtained for OFDA medullation against PM measurements. Fibre curvature for both wool and mohair was found to increase if the samples are aqueous scoured before measurement. 9 Refs.
A20.
Harig H. ,
Report of the IWTO Round Trial Part 1: Raw Wool,
Report 15, IWTO, Harrogate, June 1995.
Reports on an international round trial comparing airflow, OFDA and Laserscan. Final summary is in A24.
A21.
Baxter B.P. and Marler J.W.
Addendum to Report 15.
Estimates the confidence limits based on Report 15.
A22.
Harig H.,
Report of the IWTO Round Trial Part 2: Wool Tops,
Report 16, IWTO, Harrogate, June 1995.
Reports on an international round trial comparing PM, OFDA and Laserscan. Final summary is in A25.
A23.
Marler J.W. and Baxter B.P.
Addendum to Report 16.
Estimates the confidence limits based on Report 16.
A24.
Harig H.,
Report of the 1995 IWTO Round Trial Part 1: Raw Wool, Additional Remarks and Figures at the Harrogate Meeting,
IWTO, Harrogate, June 1995.
Provides extra graphs and conclusions to A20.
A25.
Harig H.,
Report of the 1995 IWTO Round Trial Part 2: Wool Tops, Additional Remarks and Figures at the Harrogate Meeting,
IWTO, Harrogate, June 1995.
Provides extra graphs and conclusions to A22.
A26.
Smuts S., Schleth A., Hunter L.,
OFDA Measurement of Wool Fibre Crimp - A preliminary Report,
IWTO, Nice 1995.
A group of 25 wool tops, previously measured for crimp and bulk, were measured using the OFDA fibre curve option, and the results graphed. A high correlation was found between OFDA curvature and crimp, and between OFDA curvature and bulk. 6 Refs.
A27.
Van Zyl A.M.
Comparison of Whole slide *1 versus Whole slide *2 for Mean Fibre Diameter and Standard Deviation Using OFDA,
IWTO Raw Wool Group Meeting, Nice, December 1995. Appendix 7.
A28.
Turpie D.W. Steenkamp C.H.,
Objective Measurement of Objectionable Medullated Fibres in Commercial Mohair Tops Using An Optical Fibre Diameter Analyser (OFDA): An Introductory Study,
Report No. 1. IWTO Harrogate, June 1995.
Extensive comparisons between different opacity thresholds on the OFDA were performed against visual counts of objectionable fibres in mohair. A high correlation was found between the visual and OFDA results.
A29.
Turpie D.W.F.,
Report on Round Trial No. 1 of the Working Group on "Objectionable" Medullated Fibres,
IWTO, Special Topics Group, Nice, 1995.
Reports the results of an international round trial involving 8 laboratories measuring 5 wool samples and 5 mohair samples. A good correlation was found between visually objectionable fibres and the OFDA measurement.
A30.
Peterson A.D., Gherardi S.G.,
Measurement of Cashmere Yield and Mean Fibre Diameter using the Optical Fibre Diameter Analyser (OFDA).
Western Australian Department of Agriculture, Baron-Hay Court, South Perth, WA 6151, Australia. 1995.
110 samples were measured for yield using the OFDA and the shirley analyser technique, yielding r^2 of 0.59. Measurements of mean fibre diameter were compared between OFDA and FDA. Concluded that OFDA can be used to measure the yield and diameter of cashmere to an acceptable precision. 20 Refs.
A31.
Lupton, C.J, Minikheim D.L, Pfeiffer F.A., Marschall J.R.
Concurrent Estimation of Cashmere Down Yield and Average Fibre Diameter using The Optical Fibre Diameter Analyser.
Texas Agricultural Experiment Station, Texas A&M University System, 7887 North Highway 87, San Angelo Texas 76901-9782 USA.
Two groups of 75 and 54 cashmere samples were compared for OFDA estimated yield against yield by Shirley Analyser, a correlation of r=0.91 and r=0.85 was found. Mean fibre diameter of down from the original histogram was found to be highly correlated with the mean fibre diameter measured on the down from the Shirley Analyser process. 13 Refs.
A32.
Baxter B.P.
Preliminary Investigations into the Use of OFDA for Estimating Bulk.
IWTO, Capetown Technical Report 13, April 1996
An experiment is described comparing wool samples measured by New Zealand standard NZS 8716 using a WRONZ bulkometer against a bulk estimate derived from a formula using OFDA mean diameter and OFDA fibre curvature. The results show a linear relationship. 2 Refs.
A33.
Lee J.A., Maher A.P., Frampton C.M.A., Ranford S.L
Comparison of Medullation on the Same Fibre Sites using OFDA and Projection Microscope.
IWTO, Capetown Technical Report 14, April 1996
Comparative measurements of medullation were made at the same sites on individual fibres using OFDA and projection microscope. This data was used to explore several aspects of the relationship between OFDA opacity and medullation. 11 Refs.
A34.
Turpie D.W.F.
Report on Confidence Limit Analysis Pertaining to Round Trial No. 1 of the Working Group on "Objectionable" Medullated Fibres.
IWTO Special Topics Group, Appendix 1, April 1996.
Reports the calculated confidence limits on objectionable fibres, flat fibres, total medullation, opacity, s.d. of opacity, m.f.d. of medullated fibres, m.f.d of the samples and s.d of the samples, from the round trial number 1.
A35.
Edmunds A.R.
Spreader Effects on OFDA Fibre Diameter Measurements.
IWTO Raw Wool Group Appendix 5, April 1996.
Reports the experimental comparison of 3 different spreader types and concludes that whilst the differences are small, measurements should be made using the same spreader that was used for calibration. 2 Refs.
A36.
Van Zyl, A.M.
Comparison of Wholeslide*1 Versus Wholeslide*2 for Mean Fibre Diameter and Standard Deviation using OFDA- Part II.
IWTO Raw Wool Group Appendix 4, April 1996.
Complements the results of A27 by repeating the work using the circular spreader and concludes by recommending the OFDA Test Method 47 should be altered to use wholeslide*1 instead of wholeslide*2.
A37.
Baxter B.P.
Analyses of Precision Statistics Arising From the July 1996 Medullation Round Trial.
IWTO Technology and Standards Committee, Report 2, Nice, December 1996.
Data is analysed from the medullation round trial and presented as a table of confidence limits. 3 Refs.
A38.
Turpie D.W.F.
Objectionable Medullated Fibre in Wool & Mohair- Results of Round Trial No. 2, and Comparative Results Obtained by Projection Microscope.
IWTO Technology and Standards Committee, Report 5, Nice, December 1996.
Reports the results of an international round trial involving 8 laboratories and 80 samples including scoured and tops of mohair and wool, based on the OFDA IWTO-DTM-57-96. 3 Refs.
A39.
Edmunds A.R., Summer R.M.W.
Further Data on the Use of OFDA for Estimating Raw Wool Bulk.
IWTO Technology and Standards Committee, Report 7, Nice, December 1996.
A set of 141 NZ wools from 7 breeds of sheep are measured using the NZ Standard Core Bulk Test and also for curvature and diameter by OFDA. A good linear relationship is found between Core Bulk and a linear combination of radius of curvature, mean diameter and SD of diameter. 4 Refs.
A40.
Cottle D.J., Almeida C.D., Baxter P., Petrie D.J. P
Precision of OFDA Fibre Diameter Measurements of Midside Wool Samples.
IWTO Technology and Standards Committee, Report 8, Nice, December 1996.
Reports the results and measured confidence limits of an interlaboratory round trial to be used in the Australian/New Zealand Standard for Wool Fleece Testing and Measurement (DR 96157-96163). 4 Refs.
A41.
Turpie D.W.F.
Report on Results of Round Trial on Relaxation and Some Related Investigations.
IWTO Sliver Group, Appendix 5, Nice, December 1996.
Reports the results of a round trial involving 9 laboratories on the effect of relaxation of top samples on OFDA, Airflow and Projection Microscope. No Refs.
A42.
Baxter B.P.
Preliminary Data on Diameter Distribution Differences between Projection Microscope, OFDA and Laserscan.
IWTO Sliver Group, Appendix 2, Nice, December 1996.
Presents the results on comparisons between diameter distribution data on 3 tops (31.28, 34.31, 37.11) obtained by 3 methods (OFDA, Laserscan, Projection Microscope). OFDA and Laserscan both measured slightly higher SD and CV than projection microscope. 1 Ref.
A43.
Baxter B.P, Cottle D.J.
Fibre Diameter Distribution Characteristics of Midside (Fleece) Samples and Their Use in Sheep Breeding.
IWTO Technology and Standards Committee, Report 12, Boston May 1997.
The relationship between mean fibre diameter and distribution was studied in a total of 100,000 samples from hundreds of flocks. The implications of the relationships are discussed in relation to using these measurements in sheep breeding programs. 20 Refs.
A44.
Edmunds A.R.
Relaxation, Curvature and Snippet Length Effects in Profile Diameter Measurement.
IWTO Technology and Standards Committee, Report 20, Boston May 1997.
OFDA measurements of fibre diameter and radius of curvature have been made on the current set of Interwoollabs Reference Slivers both before and after relaxation by steaming. Two different snippet lengths and full length fibres were used. Recommends a standard relaxation technique should be included in all fibre diameter measurement procedures. 12 Refs.
A45.
Edmunds A.R.
Within-laboratory Precision of OFDA Measurement of Fibre Curvature and Prediction of Bulk.
IWTO Technology and Standards Committee, Report 21, Boston May 1997.
Estimates were made of the within-laboratory precision of the values of fibre curve, radius of curvature and the predicted core bulk obtained using OFDA measurements. Satisfactory precision of predicted core-bulk should be obtained by measuring two slides per sample on the whole slide *1 setting. 5 Refs.
A46.
Brims M.
Along Fibre Diameter and Cleanliness Measurement Using OFDA.
IWTO Technology and Standards Committee, Report 23, Boston May 1997.
Introduces a new OFDA software addition to measure the diameter variation along about 200um of the snippet. From this measurement, the uniformity of the fibre can be determined, and the area of "blobs" such as residual grease is reported as a percentage. 3 Refs.