1、Designation: D7879 13 (Reapproved 2018)Standard Test Method forDetermining Flax Fiber Widths Using Image Analysis1This standard is issued under the fixed designation D7879; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method involves the measurement and analysisof two-dimensional projections of flax fibers using imageanaly
3、sis software in the longitudinal plane to determine theaverage and distribution of fiber widths.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any,
4、 associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with international
5、ly recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D123 Terminol
6、ogy Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD6798 Terminology Relating to Flax and Linen3. Terminology3.1 Definitions:3.1.1 For all terminology related to Flax and Linen seeTerminology D123.3.1.1.1 The following terms are relevant to this standard:average fiber width
7、(m).3.1.1.2 For definitions of all other textile terms see Termi-nology D6798.4. Summary of Test Method4.1 This test method involves the preparation of flax fibersfor digital capture, the scanning of the fibers for analysis, andthe calibration and standardization of the image processing.From the ima
8、ge analysis, the arithmetic mean and its standarddeviation, median, and numerical distribution of the fiberwidths are calculated.5. Significance and Use5.1 Longitudinal preparation is much quicker and lessdamaging than cross-sectional analysis and allows the fibers tobe evaluated in their natural st
9、ate.5.2 This test method provides measurement of a flax fiberspecimen that uses less specimen preparation, produces con-sistent results, and minimal specimen modification. It has beenshown that the median values of width correlate very well withthe Optical Fiber Diameter Analyzer (OFDA), an apparatu
10、sdeveloped for measuring the value and distribution of woolfiber diameters.6. Interferences6.1 Out of focus objects.6.2 Real resolution of image capturing device impactsmeasurements.6.3 Fingerprints, cracks, scratches, tape, dust and otherimpurities (non-fibrous objects) on the glass slides can bias
11、measurement results.6.4 Results will be incorrect or misleading if the operator ofthe software has not properly set up the image captureparameters.6.5 Image processing techniques employed to completemissing or incompletely developed fiber boundaries must beused with caution as false boundaries may b
12、e created.6.6 Vibrations or movement of the sample during imagecapture can blur the image and must be minimized or elimi-nated when using automatic image analysis.6.7 Non-uniform illumination can influence feature detec-tion and threshold using automatic image analyzers.6.8 Operation of the equipmen
13、t in a non-environmentallycontrolled room may result in fiber shape deviations afterinitial fiber conditioning has occurred.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.17 on Flax and Linen.Current edition approved J
14、uly 1, 2018. Published August 2018. Originallyapproved in 2013. Last previous edition approved in 2013 as D787913. DOI:10.1520/D7879-182For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf
15、ormation, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardiza
16、tion established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.17. Apparatus7.1 Fiber Preparation Apparatus:7.1.1 Acoarse comb or other device used to distribu
17、te fibersto create a single focal plane and better enable fiber edgedetection.NOTE 1Excessive overlap of fibers reduces the possibility of observ-ing all of the fibers in a single focal plane.7.1.2 Two flat surfaces capable of compressing the samplewhere at least one surface is optically transparent
18、.NOTE 2The purpose of the flat and compressive surfaces is to createa uniform focal plane to capture a majority of fibers in one focal plane.7.2 Image Capture Hardware:7.2.1 The hardware device must capture an image with areal optical resolution of at least 4000 dpi (1 dot = 6.35 m).The hardware dev
19、ice must be able to provide a digital image ina RAW format for storage and analysis.NOTE 3Stated resolution does not necessarily correspond to the realoptical resolution.7.2.2 The apparatus must be able to create a sharp image byautomatic or manual focusing.7.3 Image Analysis Software:7.3.1 Software
20、 must be capable of importing a digital image(including RAW formatted images), performing featureextraction, and calculating fiber widths for further analysis andelectronic data export.7.3.2 Software must be capable of manual or automaticadjustments so that it measures the specimen of interest (fore
21、xample, flax fiber and fiber bundles 8-100 m).7.3.3 Software must be capable of displaying the originalimage with an overlay of the feature extraction image to adjustthe threshold for proper edge detection.8. Reagents and Materials8.1 Materials may include National Institute of Standardsand Technolo
22、gy (NIST) traceable calibration images, syntheticfibers of known diameter, and components of the apparatus. Noreagents are used.9. Hazards9.1 There are no known hazards.10. Sampling, Test Specimens, and Test Units10.1 This test method describes the measurement of thesample of interest taken from the
23、 lot and is not necessarily anaccurate representation of the lots distribution. No less thanthree test specimens must be taken; additional specimens willbe dependent on the accuracy required by the end user and thenatural variation of the fibers. Due to this variation, it issuggested that at least 1
24、00 fibers be analyzed from eachspecimen.10.1.1 Gently loosen flax fibers such that individual fiberscan be accessed and extracted to produce a laboratory sample.NOTE 4The specimen should be handled gently to reduce fiber widthreduction due to fiber separation during fiber extraction. Unattached shiv
25、e,trash, and other impurities should be removed by gentle shaking.10.1.2 Take the test specimen fibers by random samplingfrom the laboratory sample.10.1.3 Use a coarse comb or other device to distribute testspecimen fibers on a flat surface thus creating a single focalplane and enabling better fiber
26、 edge detection.NOTE 5Fine combs, multiple combings, or rigorous combing, orcombination thereof, can reduce fiber width measurements.10.1.4 Use two flat surfaces capable of compressing andsecuring the fiber specimen where at least one surface isoptically transparent to create a uniform focal plane.1
27、1. Preparation of Apparatus11.1 Follow manufacturers guidelines.12. Calibration and Standardization12.1 The system must be calibrated for accurate fiber widthmeasurement.12.1.1 The scanner and software must be periodically cali-brated according to manufacturers recommendations usingimages of known d
28、imensions (for example, NIST traceableimages).12.1.2 Users are required to evaluate fiber generated imagesfor uniform edge detection and optimize the software param-eters for optimal image overlay. The software must be cali-brated to visually depict the fibers edge (generated fiberimages should over
29、lay original images with proper edgedetection).NOTE 6Edge detection may be dependent upon light source decay.13. Conditioning13.1 Bring the laboratory flax fiber sample from the prevail-ing atmosphere to moisture equilibrium for testing which is 216 1C (70 6 2F) and 65 6 2 % relative humidity and ch
30、eckthe equilibrium as directed in Practice D1776. No precondi-tioning is required.14. Procedure14.1 Prepare fiber test specimen for image capture.14.2 Follow manufacturers guidelines to acquire image offiber test specimen.14.3 Import the digital image, perform feature extraction,and determine fiber
31、widths using the image analysis software.14.4 Repeat 14.1 14.3 for remaining fiber test specimens.15. Calculation or Interpretation of Results15.1 Calculate fiber width statistics (for example, arithmeticmean fiber width, sample standard deviation, and median).NOTE 7Image analysis software may autom
32、atically generate thesestatistics.15.2 Additional reporting will be defined by agreementbetween supplier and user of the data.16. Report16.1 Report the following information:16.1.1 Identity of the laboratory sample.16.1.2 Material type.D7879 13 (2018)216.1.3 One typical image.16.1.4 Name of testing
33、laboratory.16.1.5 Type and length of preconditioning used.16.1.6 Temperature and relative humidity conditions duringtesting.16.1.7 Image capture hardware used.16.1.8 Optical resolution used.16.1.9 Type of image analysis software used, softwareparameters, and version.16.1.10 Name of operator.16.1.11
34、Date of the test.16.1.12 Number of specimens tested.16.1.13 Number of fibers examined.16.1.14 Arithmetic mean fiber width.16.1.15 Sample standard deviation.16.1.16 Median.16.1.17 Fiber width distribution curve (for test specimensand laboratory samples).16.1.18 Minimum and maximum width used during i
35、mageanalysis to isolate the objects of interest.17. Precision and Bias17.1 PrecisionThe mean, standard deviation, and 95 %repeatability limit (2.8 sample standard deviation) of within-laboratory samples tested with the same method, equipment,laboratory, and operator for various sample of flax fiber
36、areshown in Table 1.17.2 BiasWith the limitation imposed by within-laboratory evaluation, this test method has no known bias.18. Keywords18.1 fiber diameter distribution; fiber width measurement;flax fiber; image analysis; slide scannerASTM International takes no position respecting the validity of
37、any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to r
38、evision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Yo
39、ur comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is cop
40、yrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.o
41、rg (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Mean, Standard Deviation, and Within-laboratoryRepeatability LimitSample Ty
42、peAStatistic Thickness (m)1 Mean 28.59Standard deviation 2.65Repeatability Limit 7.412 Mean 56.40Standard deviation 2.88Repeatability Limit 8.073 Mean 58.63Standard deviation 6.63Repeatability Limit 18.554 Mean 27.19Standard deviation 1.65Repeatability Limit 4.635 Mean 24.61Standard deviation 0.23Re
43、peatability Limit 0.646 Mean 32.36Standard deviation 6.83Repeatability Limit 19.13AThe average and standard deviation are from three samples. The repeatabilitylimit is derived by multiplying 2.8 by the sample standard deviation in accordancewith Form and Style of ASTM Standards, Section A21.2.5.D7879 13 (2018)3
