1、Designation: E1341 06 (Reapproved 2011)1E1341 16Standard Practice forObtaining Spectroradiometric Data from Radiant Sourcesfor Colorimetry1This standard is issued under the fixed designation E1341; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year 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.1 NOTEReference to CIE Publication 015:2004 was corrected editorially throughout in November 2011.INTRO
3、DUCTIONThe fundamental procedure for characterizing the color and absolute luminance of radiant sourcesis to obtain the spectroradiometric data under specified measurement conditions, and from these datato compute CIE chromaticity coordinates and luminance values based on the CIE 1931 StandardObserv
4、er. The considerations involved and the procedures to be used to obtain precision spectrora-diometric data for this purpose are contained in this practice. The values and procedures for computingCIE chromaticity coordinates are contained in Practice E308. This practice includes minor modifi-cations
5、to the procedures given in Practice E308 that are necessary for computing the absoluteluminance of radiant sources.1. Scope1.1 This practice prescribes the instrumental measurement requirements, calibration procedures, and physical standards neededfor precise spectroradiometric data for characterizi
6、ng the color and luminance of radiant sources.1.2 This practice lists the parameters that must be specified when spectroradiometric measurements are required in specificmethods, practices, or specifications.1.3 This practice describes the unique calculation procedures required to determine basic col
7、orimetric data of luminous sources.1.4 This practice is general in scope rather than specific as to instrument, object, or material.1.5 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.6 This standard does not purport to
8、address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E275 Practic
9、e for Describing and Measuring Performance of Ultraviolet and Visible SpectrophotometersE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Using the CIE SystemE387 Test Method for Estimating Stray Radiant Power Ratio of Dispersive Spectrophotometers by the Opaque Filt
10、er MethodE925 Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Bandwidth does notExceed 2 nmE958 Practice for Estimation of the Spectral Bandwidth of Ultraviolet-Visible Spectrophotometers1 This practice is under the jurisdiction of ASTM Committee E12
11、on Color and Appearance and is the direct responsibility of Subcommittee E12.06 on Display, Imagingand Imaging Colorimetry.Current edition approved Nov. 1, 2011Nov. 1, 2016. Published November 2011November 2016. Originally approved in 1991. Last previous edition approved in 20062011as E1341 06.E1341
12、 06 (2011)1. DOI: 10.1520/E1341-06R11E01.10.1520/E1341-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.Thi
13、s document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editio
14、ns as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 NIST Publications:NIST Technical Note 594-1 Fun
15、damental Principles of Absolute Radiometry and the Philosophy of the NBS Program(19681971)3NIST Technical Note 594-3 Photometric Calibration Procedures32.3 CIE Publications:CIE Publication 015:2004 Colorimetry, 3rd ed.4CIE Publication No. 38 Radiometric and Photometric Characteristics of Materials a
16、nd their Measurement, 19774CIE Publication No. 63 Spectroradiometric Measurement of Light Sources, 198442.4 IES Standard:IES Guide to Spectroradiometric Measurements, 198352.5 ANSI Standard:ANSI/IES RP-16-1980 Nomenclature and Definitions for Illuminating Engineering53. Terminology3.1 Definitions:3.
17、1.1 The definitions of appearance terms in Terminology E284 are applicable to this practice.4. Summary of Practice4.1 Procedures are given for selecting the types and operating parameters of spectroradiometers used to produce data for thecalculation of CIE tristimulus values and other color coordina
18、tes to describe the colors of radiant sources. The important steps ofthe calibration of such instruments, and the standards required for these steps, are described. Parameters are identified that mustbe specified when spectroradiometric measurements are required in specific methods or other document
19、s. Modifications to PracticeE308 are described in order to account for the differences between objects and radiant sources.5. Significance and Use5.1 The fundamental method for obtaining CIE tristimulus values or other color coordinates for describing the colors of radiantsources is by the use of sp
20、ectroradiometric measurements. These measurements are used by summation together with numericalvalues representing the CIE 1931 Standard Observer (CIE Publication 015:2004) and normalized to Km, the maximum spectralluminous efficacy function, with a value of 683 lm/W.5.2 This practice provides a pro
21、cedure for selecting the operating parameters of spectroradiometers used for providing thedesired precision spectroradiometric data, for their calibration, and for the physical standards required for calibration.5.3 Special requirements for characterizing sources of light possessing narrow or discon
22、tinuous spectra are presented anddiscussed. Modifications to the procedures of Practice E308 are given to correct for the unusual nature of narrow or discontinuoussources.6. Requirements When Using Spectroradiometry6.1 When describing the measurement of radiant sources by spectroradiometry, the foll
23、owing must be specified.6.1.1 The radiometric quantity determined, such as the irradiance (W/m2) or radiance (W/m2-sr), or the photometric quantitydetermined, such as illuminance (lm/m2) or luminance (lm/m2-sr or cd/m2). The use of older, less descriptive names or units suchas phot, nit, stilb (see
24、ANSI/IES RP-16-1980) is not recommended.6.1.2 The geometry of the measurement conditions, including whether a diffuser was used and its material of construction, thedistances from the source of irradiation to the entrance to the spectroradiometer, and the presence of any special intermediateoptical
25、devices such as integrating spheres.6.1.3 The spectral parameters, including the spectral region, wavelength measurement interval, and spectral bandwidth.6.1.4 The type of standard used to calibrate the system, a standard lamp, a calibrated source, or a calibrated detector, and thesource of the cali
26、bration.7. Apparatus7.1 The basic instrument requirement is a spectroradiometric system designed for the measurement of spectral radiance orirradiance of light sources. The basic elements of a spectroradiometric system are calibration sources with their regulated powersupplies, a light detector, ele
27、ctronics for measuring the photocurrents, a monochromator with control equipment for computerinterfacing, receiving optics, and a computer as described in CIE Publication No. 63 and IES Guide to Spectroradiometric3 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr.,
28、 Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.4 Available from U.S. National Committee of the CIE (International Commission on Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 Pond St.,Salem, MA 01970,Alan Laird Lewis, 282 E. Riding, Carlisle, MA 01741, http:/www.
29、cie-usnc.org.5 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.E1341 162Measurements. The computer is listed as an integral part of the system since the required precision is unobtainable withoutautomated control. The cha
30、racteristics of each element are discussed in the following sections.7.2 Calibration SourcesThe standard calibration lamp for spectroradiometry is a tungsten-filament lamp operated at aspecified current. Such lamps are available from many standardizing laboratories. Typical of such standards is the
31、tungstenfilament, 1000 W, halogen cycle, quartz-envelope FEL-type lamp recommended by the National Institute of Standards andTechnology (NIST). (See NIST Technical Note 594-1, and 594-3.) Uncertainties in the transfer of the scale of spectral radianceor irradiance are about 1 %. It is preferable to
32、have more than one standard source to permit cross-checks and to allow calibrationat a range of illuminance levels. Such sources can be constructed from lamps operating at any color temperature and spectral naturethat have been characterized against a standard lamp. Monochromatic emission sources, s
33、uch as a low-pressure mercury arc lampor tunable laser, should also be available for use in calibrating the wavelength scale in accordance with Practice E925. Multilinelasers, such as continuous wave (cw) argon-ion and helium-neon, are preferred since they can be tuned to a small number of linesof w
34、ell known wavelengths.7.2.1 Calibration Source Power SuppliesThe electrical supplies for the calibration sources should be of the constant currenttype. The supply should be linear and not a switching supply. Current regulation should be maintained to better than 0.1 %. Thislevel of regulation is req
35、uired to maintain a constant flux across the entrance to the spectroradiometer.7.2.2 A standard for the measurement of length (such as a high-quality metric rule) should also be available since absoluteirradiance calibrations must be performed at exact distances from the filament of the standard lam
36、p.7.3 Detectors:7.3.1 Photomultiplier TubesPhotomultiplier tubes are the traditional detectors in spectroradiometers. This is due to theirsuperior performance in low-light-level conditions such as are encountered at the exit slit of a low-efficiency monochromator. Thephotocathodes of photomultiplier
37、s are sensitive to temperature, polarization, and magnetic fields. Light levels on the photocathodeshould never be allowed to generate photocurrents in excess of 106 A. The high-voltage supply should be stabilized to better than0.01 % since the gain of the multiplier tube is controlled by the voltag
38、e across the dynodes.7.3.2 Silicon PhotodiodesRecently, silicon photodiodes have superseded photomultiplier tubes in radiometric instruments.Photodiodes are less sensitive to temperature, polarization, and magnetic fields than photomultipliers, but care should still be takento control these variable
39、s. Two silicon photodiode based detectors used in instrumentation are Charge Coupled Devises (CCD) andComplimentary Metal Oxide Silicon (CMOS).7.4 MonochromatorsThe monochromator is the wavelength dispersive element in the system. The region of the monochro-mator should be 360 to 830 nm for highest
40、accuracy, but a region of 380 to 780 nm should suffice for most characterizations. Thebandwidth should be kept constant across the region of measurement at between 85 and 100 % of the measurement interval, butno greater than 5.0 nm. The CIE recommends a 1.0 nm bandwidth and measurement interval for
41、highest accuracy, and suggests2.0 nm as a compromise for characterizing radiation sources with spectra that contain both continuous and line emissions (CIEPublication No. 63). The precision of the wavelength setting should be 0.1 nm with an absolute accuracy of better than 0.5 nm.The size and shape
42、of the entrance and exit slits of the monochromator should be chosen to provide a symmetric bandshape,preferably triangular. The entrance slit should be completely and uniformly filled with light. Specialized versions of the generalspectroradiometer may be constructed and used for specific applicati
43、ons where the instrument can depart from the aboveguidelines. For example, a source with little or no radiant energy in the far red end of the visible spectrum may be correctlycharacterized by measurements to 700 or 710 nm rather than 780 nm.7.4.1 Scanning MonochromatorsThe newer technology of holog
44、raphically reproduced gratings has made possible theproduction of single- and double-grating monochromators with very high throughputs and very low stray-light levels. Second-orderspectra need to be eliminated through the use of either a predisperser or a long-pass filter.Adrive mechanism and positi
45、on encodershould be attached to the scanning monochromator drive to allow the monochromator to scan the wavelength region under controlof a computer. Prism-based scanning monochromators can also be used though the drive mechanism is more complex and the slitwidth must be changed as a function of the
46、 wavelength to maintain constant bandwidth.7.4.2 PolychromatorsPhotodiode arrays are used in flatfield spectrographic radiometers. The bandwidth and sampling intervalare determined by the pitch of the array and the reciprocal linear dispersion of the spectrograph. The guidelines given above shouldbe
47、 followed for the diode array instrument as well.7.5 Receiving OpticsTo maximize the light throughput, the number of optical surfaces between the source of light (either acalibration or test source) and the monochromator entrance slit should be kept to a minimum. In extended diffuse sources, onlya s
48、et of limiting apertures may be needed. For small sources a diffusing element may be required, such as a PTFE-fluorocarboncap or integrating sphere. In some instances, it may be desirable to image the source with an intermediate focusing lens or mirrorassembly. Care should be taken to use a magnific
49、ation that will adequately fill the entrance slit when viewing both the calibrationand test source. The CIE recommends the use of a rotatable integrating sphere as the input optics (CIE Publication No. 63). Theentrance port of the sphere is rotated to view first the calibration source and then to view the test source. Since the efficiency ofintegrating spheres tend to be rather low, this method is only useful for bright sources.7.6 Computer System:E1341 1637.6.1 There are no special requirements for the computer. Any minicomputer or microcomputer should suffic
