1、Designation: E1348 151Standard Test Method forTransmittance and Color by Spectrophotometry UsingHemispherical Geometry1This standard is issued under the fixed designation E1348; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEquation 1 was editorially corrected in September 2016.1. Scope1.1 This test method describes the instrumental measure
3、-ment of the transmission properties and color of object-colorspecimens by the use of a spectrophotometer or spectrocolo-rimeter with a hemispherical optical measuring system, such asan integrating sphere.1.2 This test method is generally suitable for all fullytransparent specimens without regard fo
4、r the specimen positionrelative to the transmission port of the instrument. Translucentspecimens, however, must be placed flush against the trans-mission port of the sphere.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4
5、 This standard does 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 Docu
6、ments2.1 ASTM Standards:2D1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesE179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and
7、Transmission Propertiesof MaterialsE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE805 Practice for Identification of Instrumental Methods ofColor or Color-Difference Measurement of MaterialsE1164 Practice for Obtaining Spectrometric Data for Ob
8、ject-Color Evaluation3. Terminology3.1 Definitions:3.1.1 The definitions in Guide E179, Terminology E284,and Practice E1164 are applicable to this test method.4. Summary of Test Method4.1 This test method provides a procedure for measuring thetransmittance of transmitting specimens by using a spectr
9、opho-tometer or spectrocolorimeter equipped with a hemisphericaloptical measuring system such as an integrating sphere.4.2 This test method includes procedures for calibrating theinstrument and for selecting specimens suitable for precisionmeasurement.4.3 This test method is satisfactory for all ful
10、ly transparentspecimens with plane and parallel surfaces. When possible, theuser should select the position of the specimen in the trans-mission compartment to provide either essentially total oressentially regular transmittance, depending on the end use ofthe measured data.4.4 Accurate measurement
11、of translucent specimens re-quires that the specimen be placed flush against the transmis-sion port of the integrating sphere (see Practice E1164, 8.1.4).4.5 Most modern spectrophotometers have the capacity tocompute the color coordinates of the specimen during themeasurement. When this is the case,
12、 the user of this testmethod must select the color scale, illuminant and observer(see the Procedure section in Practice E308, Section 6).5. Significance and Use5.1 The most direct and accessible methods for obtainingthe color coordinates of object colors are by instrumental1This test method is under
13、 the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.02 onSpectrophotometry and Colorimetry.Current edition approved Nov. 1, 2015. Published November 2015. Originallyapproved in 1990. Last previous edition approved in 2011 as E1348 11 DO
14、I:10.1520/E1348-15E01.2For 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 Summary page onthe ASTM website.Copyright ASTM International, 100 Barr
15、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1measurement using spectrophotometers or colorimeters witheither hemispherical or bidirectional optical measuring sys-tems. This test method provides procedures for such measure-ment by transmittance spectrophotometry using a
16、hemispheri-cal optical measuring system.5.2 This test method is especially suitable for measurementof the following types of specimens (see also Guide E179 andPractice E805):5.2.1 Fully transparent specimens (free from turbidity, haze,or translucency), and5.2.2 Translucent or hazy specimens, provide
17、d that thespecimen can be placed flush against the transmission port ofthe integrating sphere.5.3 This test method is not recommended for measurementof retroreflective transparent or translucent specimens, orsamples that are fluorescent.6. Apparatus6.1 Spectrophotometer or Spectrocolorimeter, design
18、ed forthe measurement of color coordinates of transmitting speci-mens by use of integrating-sphere geometry.6.2 Calibration Standards, either supplied by the instrumentmanufacturer or obtained separately, as follows (see PracticeE1164, Section 10):6.2.1 White Tile or Pressed-Powder Reflectance Stand
19、ard,to be placed at the reflection port of the integrating sphere(mandatory).6.2.2 Calibration Standards, for (1) setting or verifying zeroon the photometric scale; (2) verifying the wavelength scale,and (3) evaluating stray light (optional).6.2.3 Verification Standards (recommended) (see PracticeE1
20、164, 10.5).7. Test Specimen7.1 For highest precision and accuracy, select specimenswith the following properties (see Practice E1164, Section 9):7.1.1 High material uniformity and freedom from blemishesin the area to be measured, and7.1.2 Specimens that have two essentially plane and parallelsurface
21、s, and that have a standard thickness, if one is defined.8. Calibration and Verification8.1 Calibrate or verify the calibration of the followingquantities (see Practice E1164, Section 10):8.1.1 Zero setting of the transmittance scale (mandatory),8.1.2 Wavelength scale (recommended), and8.1.3 Stray-l
22、ight level (optional).8.2 Calibrate the full-scale value of the transmittance scaleof the instrument with no transmitting specimen in place andthe white reflectance standard at the reflection port. Follow theinstrument manufacturers instructions (mandatory).NOTE 1For maximum accuracy of measurement
23、of translucentspecimens, the white standard at the reflection port should have the samereflectance as that of the lining of the integrating sphere.8.3 Verify the accuracy of the measured results by measure-ment of a series of verification standards (recommended) (seePractice E1164, 10.5).9. Procedur
24、e9.1 When required, select the color scale, illuminant andobserver to be used in the computation of color coordinates(see the Procedure section in Practice E308, Section 6).9.2 Select settings of other options, such as wavelengthrange and interval, when required. Follow the instrumentmanufacturers i
25、nstructions or specified procedures.9.3 Handle the specimen carefully; avoid touching the areato be measured. When necessary, clean the specimen by anagreed procedure.9.4 For the measurement of fully transparent specimens,place the specimen in the transmission compartment of theinstrument.9.4.1 If t
26、otal transmittance is desired, place the specimenflush against the transmission measurement port of the inte-grating sphere.9.4.2 If regular transmittance is desired, place the specimenin the transmission compartment, but as far away from thesphere port as possible.9.5 For the measurement of translu
27、cent specimens, place thespecimen in the transmission compartment, flush against thetransmission measurement port of the integrating sphere. Formaximum accuracy in the measurements, the white standard atthe reflection port should have the same reflectance as that ofthe lining of the integrating sphe
28、re (see Practice E1164, 8.1.4).NOTE 2When the size and centering of the light beam at the reflectionmeasurement port of the integrating sphere can be properly adjustedaccording to Test Method D1003, it is possible to measure transmissionhaze accurately. A set of haze standards should be used to veri
29、fy theaccuracy of the measurements.9.6 Measure the specimen, following the instrument manu-facturers instructions.9.7 Transcribe the data required for the report, when notprinted by the instrument.10. Calculation10.1 Perform any desired calculations of color coordinatesthat are not made automaticall
30、y by the instrument (see PracticeD2244 and Practice E308).11. Report11.1 Report the following information:11.1.1 Specimen description (see Practice E1164, 12.1.1),11.1.2 Date of measurement,11.1.3 Instrument parameters and specimen position asselected in Section 9, and11.1.4 Measurement results, in
31、the form of tables of trans-mittance versus wavelength or color-scale values.12. Precision and Bias12.1 PrecisionThe precision estimates are composed ofthree additive terms. The first term represents the noisecomponent of any measurement. The second term representsmeasurement uncertainty introduced
32、by factors dependentupon the first derivative of the transmittance function of thespecimen. The third term represents uncertainty introduced byE1348 1512factors dependent upon the absolute magnitude of the trans-mittance value at any wavelength. For complex transmittancefunctions such as a didymium
33、filter a more complex model ofthe derivative is required than the linear model offered here.Hence complex spectra may be expected to fail the testdescribed below at or near their transmittance maxima andminima. In addition, reporting intervals greater than 10 nmmay also fail.12.1.1 RepeatabilityMeas
34、urements should be consideredsuspect if the sample standard deviation of four spectraltransmittance values measured under repeatability conditions islarger at most wavelengths than the limit defined by thefollowing equation:max! 5 0.021ABSFT 2 10! 2 T110!200G1T!1000(1)where:max() = maximum allowable
35、 sample standard deviation atany wavelength,T() = mean of four readings of T at that wavelength andthe units of T() are percent transmittance, and = wavelength in nm currently under consideration.The units of the calculated limit are therefore percenttransmittance. A 10 nm wavelength measurement int
36、erval isassumed in this example. For measurements at 20 nm interval,the constants in the second additive term are 20, 20, and 400respectively. In either case, the first and last measured intervalsare ignored.12.1.2 ReproducibilityMeasurements should be consid-ered suspect if the absolute value of th
37、e difference between twospectral transmittance values measured under reproducibilityconditions is larger at most wavelengths than the limit definedby the following equation:T! 5 0.081ABSFT 2 10! 2 T110!200G1T!100(2)where the units, symbols, and procedure are identical tothose of Eq 1.NOTE 3Sometimes
38、 one of the two spectral transmittance valuesmeasured under reproducibility conditions is the set of tabular values of acalibration verification standard, and the other set of values is thatverification standard measured on an individual instrument for the purposeof verification of calibration of th
39、e instrument. Under these conditions, ifthe pair fails the above test, the instrument may be considered suspect, andmay fail calibration verification.12.2 BiasThere is no known bias in this method.13. Keywords13.1 color; integrating sphere; spectrophotometer; translu-cent; transmittance; transparent
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