BS 8475-2006 Instrumental colour measurement of textiles - Method《织物颜色的仪器测量 方法》.pdf

1、BS 8475:2006Instrumental colour measurement of textiles MethodICS 59.080.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the document was last issued. BSI 10

2、 FEBRUARY 2006ISBN 0 580 47826 2The following BSI references relate to the work on this standard:Committee reference TCI/81Draft for comment DC01/124129Publication historyFirst published February 2006Amendments issued since publicationAmd. no. Date Text affectedBS 8475:2006 BSI FEBRUARY 2006 iBS 847

3、5:2006ContentsForeword iii1 Scope 12 Normative references 13 Principle 14 Apparatus 15 Preparation of specific types of specimen 26 Conditioning 37 Presentation of specimens 38 Procedure for colour measurement 49 Test report 6Annex A (normative) Specific methods of specimen preparation 7Annex B (inf

4、ormative) Colour measurement of fluorescent specimens 10Bibliography 12Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 12, an inside back cover and a back cover.BS 8475:2006ii BSI FEBRUARY 2006 This page deliberately left blank BSI FEBRUARY 200

5、6 iiiBS 8475:2006ForewordPublishing informationThis British Standard was published by BSI and came into effect on 10 February 2006. It was entrusted by Technical Committee TCI/81, Colour fastness and colour measurement, to Working Group 3 of the Colour Measurement Committee of the Society of Dyers a

6、nd Colourists. A list of organizations represented on this committee can be obtained on request to its secretary.Information about this documentColour measurement of textiles has become increasingly important. Errors in colour measurement are usually caused by either a non-representative specimen be

7、ing measured or incorrect or inconsistent presentation of the specimen to the measuring instrument.This standard is intended to provide procedures for the preparation and presentation of all types of textile materials in order to enable their colour to be measured consistently and reproducibly.The p

8、rocedures may be used in the determination of:a) the absolute colour specification of a single specimen (Notes 1, 2 and 3) or of a number of specimens to be used together in the construction of a match prediction database;b) the colour difference between areas of a single specimen (Note 4);c) the co

9、lour difference between specimens (Note 4)d) colour formulations and colour corrections by computer match prediction.NOTE 1 The method may be used in defining and measuring the colours associated with specifications such as BS 3510, BS 381C, BS 5455, BS 6341 and BS EN 471.NOTE 2 The recommended meth

10、od for calculating the absolute colorimetric values of a coloured specimen is the CIE 1976 L*a*b* (CIELAB) equation (see Publication CIE 15).NOTE 3 The recommended method for calculating the whiteness values of a white specimen is the CIE whiteness equation (see Publication CIE 15).NOTE 4 The recomm

11、ended method for calculating the colour difference within a single specimen or between specimens measured under identical conditions is the CMC (l:c) equation given in BS EN ISO 105-J03, which provides a numerical value E the total colour difference, which quantifies the perceptibility or the accept

12、ability of the colour match. The direction of the colour difference is given by the components L, C and H.NOTE 5 The symbol (for difference) is often replaced by D, giving DE, DL, DC and DH.Presentational conventionsThe provisions in this standard are presented in roman (i.e. upright) type. Its reco

13、mmendations are expressed in sentences in which the principal auxiliary verb is “shall”.Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.BS 8475:2006iv BSI FEBRUARY 2006Contractual and legal considerationsThis p

14、ublication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. BSI FEBRUARY 2006 1BS 8475:20061 ScopeThis British Standard specifies procedures to b

15、e used in preparing representative textile materials for presentation to an instrument appropriate for the measurement of surface colour. It includes procedures for acquiring the data for the determination of a numerical colour specification.2 Normative referencesThe following referenced documents a

16、re indispensable for the application of this document. For dated references, only the reference cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.BS EN ISO 105-B05, Textiles Tests for colour fastness Part B05: Detection and assess

17、ment of photochromismBS EN ISO 105-J03, Textiles Tests for colour fastness Part J03: Calculation of colour differencesBS EN ISO 139, Textiles Standard atmospheres for conditioning and testingBS EN ISO 3696, Water for analytical laboratory use Specification and test methods.CIE Publication 15:2004. C

18、olorimetry (3rd edition). Vienna: CIE Commission Internationale de lEclairage, 20041)IWTO-35-03, Method for the measurement of colour of sliver. International Wool Textile Organisation http:/www.iwto.orgIWTO-56-03, Method for the measurement of base and “as is” colour of raw wool. International Wool

19、 Textile Organisation http:/www.iwto.org3 PrincipleThe specimen is prepared and presented to the aperture of the selected instrument and its colour is measured.4 Apparatus4.1 Spectrophotometer, using one of the optical geometries specified in CIE Publication 15, for the measurement of reflectance th

20、roughout the visible spectrum. The preferred optical geometry of specimen illumination and viewing is diffuse/normal (d/0) as defined in CIE 15. NOTE The angle between the normal to the specimen and the axis of the viewing beam should not exceed 10.4.2 Tristimulus colorimeter, which may be used only

21、 for colour comparisons of non-metameric materials.1)Available from The Secretary, NIC/GB, c/o CIBSE, Delta House, 222 Balham High Road, London SW12 9BS, or The CIE Central Bureau, Kegelgasse 27, A-1030, Vienna, Austria. http:/www.cie.co.at/cie BS 8475:20062 BSI FEBRUARY 20065 Preparation of specifi

22、c types of specimen5.1 FibresLoose fibre, sliver or tow specimens shall be prepared in accordance with one of the methods described in A.1, A.2 or A.3 respectively.5.2 Spun and continuous filament yarn specimens5.2.1 Yarn used for fabric and sewing threadsYarn used for fabric shall be, either:a) wou

23、nd from the original package onto a former in accordance with A.4, with consistent tension, to provide a flat opaque specimen; orb) knitted under controlled conditions on a knitting machine and folded to provide sufficient thickness so as to be opaque (see Clause 7), and then presented directly to t

24、he instrument for measurement.Yarn used for sewing threads shall be prepared as in a).5.2.2 Carpet yarnYarns used for cut pile carpets shall be prepared by a cross cutting method in accordance with A.5. Where possible, specimens shall be viewed tuft end-on.5.3 Fabrics5.3.1 Woven, knitted, non woven

25、and coated fibre structures The face and orientation of the specimens shall be identified. The specimen shall be folded if necessary to provide sufficient thickness so as to be opaque (see Clause 7).NOTE Most woven fabrics and knitted goods require no special specimen preparation.5.3.2 Pile fabricsB

26、efore measurement, pile fabrics shall be brushed in the direction of the pile.5.4 CarpetsBefore measurement, cut pile carpets shall be brushed in the direction of the natural pile lay. BSI FEBRUARY 2006 3BS 8475:20066 ConditioningThe atmosphere for preconditioning and conditioning specimens shall be

27、 as specified in BS EN ISO 139.NOTE The colour of specimens can be significantly affected by temperature and humidity.To ensure stabilization of colour, condition specimens at (20 2) C and (65 2) % relative humidity for a minimum of 30 min immediately prior to colour measurement. Adjust the conditio

28、ning time accordingly for those specimens requiring a longer conditioning time to ensure stabilization of colour. Where there is any doubt about the stability of the colour, check by returning the specimen (after colour measurement) to the conditioning environment for a further 15 min then measure t

29、he colour again. If the colour difference between these two measurements is within CMC(2:1) E = 0.2, the prepared specimen is adequately conditioned.If the colour of the specimen is affected by light, include exposure to a source simulating CIE Standard Illuminant D65 in the conditioning process. To

30、 determine whether a sample is affected by light (photochromic), test in accordance with BS EN ISO 105-B05.In order to avoid significant change in the condition, and regardless of the nature of their conditioning, measure specimens removed from the conditioning environment immediately thereafter.7 P

31、resentation of specimensThe specimen shall be of a size adequate to completely cover the aperture of the instrument. Measurement shall be with the largest aperture possible. An area of the specimen that is uniform in colour, evenly constructed and clean shall be presented to the aperture of the inst

32、rument, avoiding specimen irregularities or spots visible to the eye in the measurement.The specimen shall be of sufficient thickness so as to be opaque. All specimens shall be measured in the same thickness where the colour difference between specimens is being measured.NOTE 1 Establishing opacity

33、will depend upon the nature of the specimen, e.g. fabric should be folded and yarn should be wound in multiple layers. If a specimen is not opaque, light passing through it will reflect from the backing material or holder causing an erroneous measurement. The opacity of a specimen may be checked by

34、measuring it over a black background, and separately over a white background. If the colour difference between these two measurements is within CMC(2:1) E = 0.2, the prepared specimen is adequately opaque.NOTE 2 Care should be taken not to increase the thickness of the specimen beyond that which is

35、necessary to achieve practical opacity in order to avoid intrusion of the specimen beyond the plane of the measurement port of the instrument, which can itself cause error in measurement.Present the specimen to the instrument in a flat and relaxed state.NOTE 3 Excessive tension on the mounted specim

36、en can cause distortion, leading to erroneous measurements. If the mounting is too slack, shadows can appear from the attendant wrinkling, giving incorrect measurements.BS 8475:20064 BSI FEBRUARY 20068 Procedure for colour measurement8.1 Instrument performance and maintenanceThe manufacturers recomm

37、endations for monitoring instrument performance and maintenance shall be followed.8.2 Standardization of the instrumentNOTE Standardization is often referred to as calibration; the former is the preferred term.Switch on the instrument and allow sufficient time for stabilization in accordance with th

38、e manufacturers recommendations. Select the measurement conditions required for standardization of the instrument being used: wavelength range and interval (for spectrophotometer); size of aperture; specular component included or excluded; control of ultraviolet content of the light source (see Anne

39、x B).NOTE The sequence to be followed varies from one instrument to another.Standardize the instrument in accordance with the manufacturers recommendations. During the use of the instrument, repeat the standardization at regular intervals in accordance with the manufacturers recommendations, but avo

40、id re-standardization during related measurements. 8.3 Measuring the specimen(s)The sequence to be followed varies from one instrument to another, but shall include all the following steps.a) Select the method of preparation and presentation of the specimens. If required, select the number of repeat

41、 measurements.b) If the instrument conditions required to measure the specimen are not those used during standardization, adjust as required.c) Measure the colour of the specimen(s).d) Select the requirements for calculation of the data:1) illuminant(s);2) observer(s).NOTE 1 The preferred illuminant

42、/observer weights are listed in ASTM E308-01.NOTE 2 The preferred observer, in most applications, is the CIE 1964 standard colorimetric observer (10).e) Select the parameters to be output:1) absolute colour co-ordinates;2) colour difference equation(s) and results.f) Output and record the data as re

43、quired. BSI FEBRUARY 2006 5BS 8475:20068.4 Specular component of measurementsThe specular component of measurement shall be taken into account as follows.a) Measure non-glossy specimens with the specular component included.b) When making comparisons between two specimens which show different levels

44、of gloss, measure both specimens with the specular component excluded.c) Measure glossy specimens with the specular component excluded.NOTE 1 Glossy specimens are those for which there is a significant difference between measurements made with the specular component included and excluded.NOTE 2 The

45、practice of measuring the reflectance of specimens behind glass alters the measurements significantly and should be avoided if possible. For certain types of specimen, such as some loose fibre samples, measurement behind glass is necessary and the requirements specified in A.1.2 should be followed.

46、If a specimen has to be measured behind glass, an appropriate correction should be made, e.g. as in IWTO-56-03. 8.5 ConsistencySpecimens shall be measured to within CMC(2:1) E = 0.2 between replicate measurements in order to achieve consistency in accordance with BS EN ISO 105-J03. NOTE This may be

47、accomplished by taking multiple measurements, moving the specimen between measurements without changing its orientation, and obtaining average values. 8.6 Fluorescent specimensAdvice on colour measurement of fluorescent specimens is given in Annex B. Measurement of fluorescent white specimens is dis

48、cussed in B.1 and coloured fluorescent specimens in B.2.8.7 Measurement of colour differenceWhere the colour difference between specimens is required:a) instrument settings shall be the same for each measurement, i.e. specular component included/excluded, ultraviolet component included/excluded and

49、aperture size;b) specimens shall be prepared and presented to the instrument selected by identical procedures;c) wherever practicable and the surface direction can be specified, specimens shall be measured in the same orientation.BS 8475:20066 BSI FEBRUARY 20069 Test reportThe test report shall contain at least the following information:a) the number and date of this British Standard, i.e. BS 8475:2006;b) the date when the test was carried out;c) the specimen identification details