1、Designation: D2985/D2985M 92 (Reapproved 2011)1Standard Test Method forColor of Asbestos1This standard is issued under the fixed designation D2985/D2985M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits information was editorially corrected in February 2012.1. Scope1.1 This test method covers the determination of color,whiteness, and ye
3、llowness of asbestos by means of a photo-electric reflectometer.1.2 The test method is applicable to all grades and varietiesof homogeneous milled asbestos.1.3 This test method may be applied to samples that are notdry or homogeneous, or that contain impurities or adulterants.However, in such cases,
4、 results may not be comparable withthose obtained on clean dry samples.1.4 To obtain similar results from spectrophotometers, seeTest Method E308.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact eq
5、uivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and for those wi
6、th whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the safe use of chrysotile asbestos, refer to “Safe Use ofChrysotile: A Manual of Preventive and Control Measures.”21.7 This standard does
7、not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standa
8、rds:3D2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD2590 Test Method for Sampling Chrysotile AsbestosD2946 Terminology for Asbestos and AsbestosCementProductsD3879 Test Method for Sampling Amphibole Asbestos4E3 Guide for Preparat
9、ion of Metallographic SpecimensE259 Practice for Preparation of Pressed Powder WhiteReflectance Factor Transfer Standards for Hemisphericaland Bi-Directional GeometriesE308 Practice for Computing the Colors of Objects byUsing the CIE System3. Terminology3.1 Definitions of Terms Specific to This Stan
10、dard:53.1.1 black, adj, adjcolor name applied to opaque objectsthat are highly absorbing throughout the visible spectrum.3.1.2 CIE, nacronym for International Commission onIllumination, which in French is Commission Internationale delEclairage.3.1.3 CIE observer, nSee observer, standard, CIE 1931and
11、 observer, supplementary, CIE 1964.3.1.4 CIE source C, nSee standard source.3.1.5 color, psychophysical, ncharacteristics of a colorstimulus (that is, light producing a sensation of color) denotedby three dimension values such as three tristimulus values.1This test method is under the jurisdiction o
12、f ASTM Committee C17 onFiber-Reinforced Cement Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos - Cement Sheet Products and Accessories.Current edition approved Nov. 1, 2011. Published February 2012. Originallyapproved in 1971. Last previous edition approved in 2006 as D29
13、85 92 (2006).DOI: 10.1520/D2985_D2985M-92R11E01.2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Sum
14、mary page onthe ASTM website.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.5Taken in part from Procedure No. B5-9 of Socete Asbestos Ltee, withpermission.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29
15、59, United States.3.1.6 daylight 0.785 rad, 0 rad (45, 0) luminous direc-tional reflectancedaylight 0.785 rad, 0 rad (45, 0) lumi-nous directional reflectance (for brevity called reflectance) isthe ratio of the luminous flux from a specimen illuminated at anangle of 0.785 rad (45) by CIE standard so
16、urce C6(averagedaylight) and viewed perpendicularly by the CIE standardobserver, to the luminous flux from the standard magnesiumoxide layer, similarly illuminated and viewed (Note 1). Thecombination of illumination at 0.785 rad (45) and viewing at0 rad (0) (perpendicularly) has been selected as bei
17、ng repre-sentative of average conditions of illuminating and viewing.The property of reflectance determines which of two specimenswill appear lighter when viewed in average daylight at an angleat which the observation of highlights is avoided.NOTE 1These conditions of illumination and observation ma
18、y beinterchanged without affecting the results.3.1.7 glos, nangular selectivity of reflectance of surface-reflected light responsible for the degree to which reflectedhighlights or images of objects may be seen as superimposedon a surface.3.1.8 gloss, specular, nratio of flux reflected in a specular
19、direction to incident flux for specific source and receptorapertures (usually measured relative to a standard of specifiedindex of refraction).3.1.9 gray, ncolor name applied to achromatic stimuli ofmoderate relative luminance.3.1.10 green, adjhue name applied to light of wave-lengths from 495 to 55
20、0 nm.3.1.11 hue, nattribute of color perception by means ofwhich objects are judged to be red, yellow, blue or intermediatebetween some adjacent pair of these. Hue is a matter of socialconsensus as opposed to an assigned frequency range.3.1.12 ideal black, nobject or material that absorbs alllight i
21、mpinging on it.3.1.13 illuminant, nincident luminous flux specified onlyby its spectral distribution. (The spectral composition of anilluminant may differ from the source because of spectralmodification by such means as absorption or refraction bymediae enclosing the source or by reflection from oth
22、erobjects. See definition of source. The CIE standard illuminantsare Illuminant C and Illuminant D6500, each representingaverage daylight, and Illuminant A, 2854K).3.1.14 light, nelectromagnetic radiation in the spectralrange detectable by the normal human eye (approximately 380to 760 nm).3.1.15 lig
23、ht, nradiant energy evaluated according to theCIE photopic spectral luminous efficiency function.3.1.16 light, adjhighly reflecting, as in the term lightgreen.3.1.16.1 DiscussionFor given conditions of illuminationand surface texture, a more reflective surface is perceived aslighter in color than a
24、less reflective but otherwise identicalsurface.3.1.17 luminous, adjindicates that the radiant flux isevaluated by weighting according to the luminous efficiencyfunction of the CIE 1931 standard observer.3.1.18 luminous reflectance, nSee reflectance, luminous.3.1.19 observer, standard, CIE 1931, nhyp
25、othetical ob-server based on color mixture data obtained for a 2 field ofview for 17 observers, adopted by the CIE in 1931.3.1.20 observer, supplementary, CIE 1964, nhypotheticalobserver based on color mixture data obtained for a 10 field ofview for 76 observers, adopted by the CIE in 1964.3.1.21 ph
26、otoelectric color meter, ncolor-stimulus-measuring instrument using photoelectric detectors in whichsource-filter-detector response characteristics are adjusted sothat the instruments read directly the tristimulus values orrelated quantities.3.1.22 preferred white, nthe white color, usually bluish,t
27、hat is judged by a given group of observers looking at a givenseries of specimens to be the whitest color attainable.3.1.23 reflectance, luminous, nratio of luminous fluxreflected by a specimen to that incident on it.3.1.24 reflection, nprocesses by which incident fluxleaves a surface or a medium fr
28、om the incident side.3.1.25 reflection, diffuse, nprocess by which incident fluxis distributed by reflection over a wide range of angles.3.1.26 regular, adjused to indicate flux transmitted orreflected in the image-forming state (the adjective specular isusually used to indicate regular mirror-refle
29、cted flux).3.1.27 source, nthat which furnishes light or other radia-tion; real device by which radiant flux is produced. (Seeilluminant.)3.1.28 source, CIE standard, nSee standard source.3.1.29 spectral, adjindicates either a function of wave-length as in spectral transmittance, or spectral concent
30、ration, asin spectral flux.3.1.30 specular, adjsame as regular when applied toreflection.3.1.31 specular gloss, nSee gloss, specular.3.1.32 standard observer, nSee observer, standard.3.1.33 standard, primary, none whose calibration is de-termined by measurement according to specified parameters.3.1.
31、34 standard, secondary, nstandard calibrated by ref-erence to another standard such as a primary, reference,laboratory or working standard.3.1.35 standard source, nlight source whose spectralenergy distribution is known or defined. (The CIE standardsources to represent incandescent-lamp light, sunli
32、ght, anddaylight, are designated A, B, and C, respectively.)3.1.36 texture, adjin evaluating the color of a surface,structural quality of a surface determined by the topography ofits constituents.3.1.37 viewing conditions, nthe conditions under which avisual observation is made, including the angula
33、r substance ofthe specimen at the eye; the geometric relationship of source,specimen and eye; the photometric and spectral character of thefield of view surrounding the specimen; and the state ofadaptation of the eye.3.1.38 white, adjcolor name most usually applied toopaque, highly reflecting, highl
34、y diffusing, visually huelessspecimens.6CIE standard sources and functions are defined in Test Method E308.D2985/D2985M 92 (2011)123.1.39 whitenessthe term “whiteness” is widely used todesignate the degree to which a near-white surface approaches“perfect white,” defined as a 100 % reflectance over t
35、he wholevisible spectrum. Other terms used for this property are“lightness” or“ luminous apparent reflectance.” The concept ofwhiteness is not only applicable to near-white surfaces but alsoto dark and colored surfaces. Whiteness may be defined as thegrading which an observer would assign to the sur
36、face,irrespective of its color or hue, when compared under daylightconditions against a scale of grays ranging from white to black.3.1.40 yellow, adjhue name applied to light wavelengthsfrom 572 to 783 nm and to visually similar stimuli.3.1.41 yellownessa yellowed or tan discolored asbestosmay have
37、the same degree of whiteness on the gray scale as agray asbestos. It is thus necessary to measure an index ofyellowness for such cases, and this may be calculated arbi-trarily from reflectance measurements using tristimulus filters.Use the following relationship for asbestos:yellowness factor 5 A 2
38、B!/G (1)where:A = reflectance with the amber tristimulus filter,6B = reflectance with the blue tristimulus filter, andG = reflectance with the green tristimulus filter.3.1.42 For terms relating to asbestos fibers, refer to Termi-nology D2946.4. Summary of Test Method4.1 Specimens are pressed into a
39、pellet and the luminousreflectance is measured by means of a simple reflectometerfitted with an incandescent source, and a photoelectric reflec-tometer.4.2 Instructions are included for use of the suppressed zerotechnique to improve precision.4.3 The use of tristimulus color filters permitting the d
40、eter-mination of whiteness, yellowness, and CIE8color-order val-ues, is covered.5. Significance and Use5.1 The color of asbestos is of commercial significancewhen it is to be incorporated into products, the color of whichis affected by the color of the asbestos, and for which colorspecifications mus
41、t be met.5.2 Whiteness is required of asbestos for use in white orpale-colored products.5.3 Yellowness is significant in asbestos for use in pastel-colored products where discolored asbestos may prevent at-tainment of certain shades and hues detector.6. Apparatus6.1 The apparatus shall consist of a
42、photoelectric reflecto-meter having source, filter, and receptor characteristics suchthat it will measure reflectance accurately to within 1.0 % offull-scale reading. The reflectometer shall have the followingcharacteristics:6.1.1 Spectral CharacteristicsThe spectral energy distri-bution of the illu
43、minator and the spectral sensitivity of thereceptor, in combination, shall provide the equivalent ofillumination by CIE standard source C and observation by theCIE standard observer.6.1.2 Geometric CharacteristicsIllumination shall bewithin 0.0698 rad (4) of, and centered about, a direction of0.785
44、rad (45) from the perpendicular to the test surface;viewing shall be within 0.262 rad (15) of, and centered about,the perpendicular (Note 1).6.1.3 Any instrument that meets the apparatus specificationsand the precision requirements stated in Section 13 may beused. In general, commercial instruments
45、do not conformexactly to the apparatus requirements. The suitability of agiven instrument depends in large measure on its response tothe spectral selectivity range of asbestos, and on the availabil-ity of standards of similar reflectance and spectral character.Instruments that have been found satisf
46、actory include: theHunter Multi-purpose Reflectometer; the Gardner (Hunter)Photometric Unit with 0.785 rad, 0 rad (45, 0) reflectancehead; and the General Electric Reflection Meter.6.2 Standards:6.2.1 Primary StandardThe primary standard for reflec-tance measurements is a layer of MgO freshly prepar
47、ed inaccordance with Practice E259. It is assigned a value of 100 forthe conditions of 0.785 rad (45) illumination and perpendicu-lar view (Note 1).6.2.2 Secondary StandardsPorcelain enameled metalplaques or other materials known to be reasonably permanentin reflectance, and of uniform surface, may
48、be calibrated andused as secondary reflectance standards.NOTE 2Secondary standards of porcelain enamel may be obtainedfrom the National Bureau of Standards,9the Henry A. Gardner Labora-tory,10or the Photovolt Corp. Experience has shown that these secondaryreflectance standards are reasonably permane
49、nt if abrasion is avoided.Plaques stored for a year or more may develop efflorescence (bloom)noticeable on black plaques, which can be removed by washing with mildsoluble soap and water.6.2.3 Standards with reflectance values as close as possibleto the values of the unknowns are recommended.6.3 Tristimulus Filters,7including amber, blue, and green,to fit the reflectometer source and detector.6.4 Piston and Cylinder Mold, for pressing the asbestosspecimens into pell
