1、Designation: G 130 06Standard Test Method forCalibration of Narrow- and Broad-Band UltravioletRadiometers Using a Spectroradiometer1This standard is issued under the fixed designation G 130; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONAccurate and precise measurements of ultraviolet irradiance are required in the determination of
3、theradiant exposure of both total and selected narrow bands of ultraviolet radiation for the determinationof exposure levels in (1) outdoor weathering of materials, (2) indoor accelerated exposure testing ofmaterials using manufactured light sources, and (3) UV-Aand UV-B ultraviolet radiation in ter
4、ms bothof the assessment of climatic parameters and the changes that may be taking place in the solarultraviolet radiation reaching earth.Although meteorological measurements usually require calibration of pyranometers and radiom-eters oriented with axis vertical, applications associated with materi
5、als testing require an assessmentof the calibration accuracy at orientations with the axis horizontal (usually associated with testing inindoor exposure cabinets) or with the axis at angles typically up to 45 or greater from the horizontal(for outdoor exposure testing). These calibrations also requi
6、re that deviations from the cosine law, tilteffects, and temperature sensitivity be either known and documented for the instrument model ordetermined on individual instruments.This test method requires calibrations traceable to primary reference standards maintained by anational metrological laborat
7、ory that has participated in intercomparisons of standards of spectralirradiance.1. Scope1.1 This test method covers the calibration of ultravioletlight-measuring radiometers possessing either narrow- orbroad-band spectral response distributions using either a scan-ning or a linear-diode-array spect
8、roradiometer as the primaryreference instrument. For transfer of calibration from radiom-eters calibrated by this test method to other instruments, TestMethod E 824 should be used.NOTE 1Special precautions must be taken when a diode-array spec-troradiometer is employed in the calibration of filter r
9、adiometers havingspectral response distributions below 320-nm wavelength. Such precau-tions are described in detail in subsequent sections of this test method.1.2 This test method is limited to calibrations of radiometersagainst light sources that the radiometers will be used tomeasure during field
10、use.NOTE 2For example, an ultraviolet radiometer calibrated againstnatural sunlight cannot be employed to measure the total ultravioletirradiance of a fluorescent ultraviolet lamp.1.3 Calibrations performed using this test method may beagainst natural sunlight, Xenon-arc burners, metal halideburners
11、, tungsten and tungsten-halogen lamps, fluorescentlamps, etc.1.4 Radiometers that may be calibrated by this test methodinclude narrow-, broad-, and wide-band ultraviolet radiom-eters, and narrow-, broad, and wide-band visible-region-onlyradiometers, or radiometers having wavelength response dis-trib
12、utions that fall into both the ultraviolet and visible regions.NOTE 3For purposes of this test method, narrow-band radiometers arethose with Dl # 20 nm, broad-band radiometers are those with 20 nm#Dl # 70 nm, and wide-band radiometers are those with Dl $ 70 nm.1This test method is under the jurisdic
13、tion of ASTM Committee G3 onDurability of Nonmetallic Materials and is the direct responsibility of SubcommitteeG03.09 on Solar and Ultraviolet Radiation Measurement Standards.Current edition approved June 1, 2006. Published July 2006. Originally approvedin 1995. Last previous edition approved in 20
14、02 as G 13095(2002)1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 4For purposes of this test method, the ultraviolet region isdefined as the region from 285 to 400-nm wavelength, and the visibleregion is defined as the region f
15、rom 400 to 750-nm wavelength. Theultraviolet region is further defined as being either UV-A with radiation ofwavelengths from 315 to 400 nm, or UV-B with radiation from 285 to315-nm wavelength.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I
16、t 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 Standards:2E 772 Terminology Relating to Solar Energy ConversionE 824 Test Method for Tran
17、sfer of Calibration From Refer-ence to Field Radiometers3. Terminology3.1 Definitions:3.1.1 broad-band radiometera relative term generallyapplied to radiometers with interference filters or cut-on/cut-offfilter pairs having a FWHM between 20 and 70 nm and withtolerances in center (peak) wavelength a
18、nd FWHM no greaterthan 62 nm.3.1.2 diode array detectora detector with from 50 to 1000silicon photodiodes affixed side-by-side in a linear array andmounted in the focal plane of the exit slit of a monochromator.3.1.3 full width at half maximum (FWHM)in a bandpassfilter, FWHM is the interval between
19、wavelengths at whichtransmittance is 50 % of the peak, frequently referred to asbandwidth.3.1.4 narrow-band radiometera relative term generallyapplied to radiometers with interference filters with FWHM#20 nm and with tolerances in center (peak) wavelength andFWHM no greater than6 2 nm.3.1.5 scanning
20、 monochromatora monochromator thatuses either a single, or several interchangeable, detector(s)mounted at the exit slit, that is presented with dispersed lightby sweeping the spectrum across the slit to illuminate thedetector with a succession of different very narrow wavelengthlight distributions.
21、The detector may be either a photomulti-plier tube (PMT) or silicon photodiode (visible), or a PMT oran ultraviolet-enhanced silicon photodiode (ultraviolet andvisible), or a lead sulfide cell or other solid state detector (nearinfrared), etc. The dispersed spectrum is swept across themonochromators
22、 exit slit using a mechanical stage that rotateseither a prism or a grating dispersive element, usually under thecontrol of an external microprocessor or computer.3.1.6 spectroradiometera radiometer consisting of amonochromator with special acceptance optics mounted to theentrance aperture and a det
23、ector mounted to the exit aperture,usually provided with electronic or computer encoding ofwavelength and radiometric intensity. The monochromator ofsuch instruments is either of the linear diode (often called diodearray) or the scanning type.3.1.7 wide-band radiometera relative term generally ap-pl
24、ied to radiometers with combinations of cut-off and cut-onfilters with FWHM greater than 70 nm.3.2 For other terms relating to this test method, see Termi-nology E 772.4. Significance and Use4.1 This test method represents the preferable means forcalibrating both narrow-band and broad-band ultraviol
25、et radi-ometers. Calibration of narrow- and broad-band ultravioletradiometers involving direct comparison to a standard sourceof spectral irradiance is an alternative method for calibratingultraviolet radiometers. An ASTM test method describing thisprocedure is under development by Subcommittee G03.
26、09 onRadiometry.4.2 The accuracy of this calibration technique is dependenton the condition of the light source (for example, cloudy skies,polluted skies, aged lamps, defective luminaires, etc.), and onsource alignment, source to receptor distance, and sourcepower regulation.NOTE 5It is conceivable
27、that a radiometer might be calibrated againsta light source that represents an arbitrarily chosen degree of aging for itsclass in order to present to both the test and reference radiometers aspectrum that is most typical for the type.4.3 Spectroradiometric measurements performed using ei-ther an int
28、egrating sphere or a cosine receptor (such as a shapedTFE3,orAl2O3diffuser plate) provide a measurement ofhemispherical spectral irradiance in the plane of the spheresentrance port. As such, the aspect relative to the reference lightsource must be defined (azimuth and tilt from the horizontal forsol
29、ar measurements, normal incidence with respect to the beamcomponent of sunlight, or normal incidence and the geometri-cal aspect with respect to an artificial light source, or array). Itis important that the geometrical aspect between the plane ofthe spectroradiometers source optics and that of the
30、radiom-eter being calibrated be as nearly identical as possible.NOTE 6When measuring the hemispherical spectral energy distribu-tion of an array of light sources (for lamps), normal incidence is definedby the condition obtained when the plane of the spheres aperture isparallel to the plane of the la
31、mp, or burner, array.4.4 Calibration measurements performed using a spectrora-diometer equipped with a pyrheliometer-comparison tube (asky-occluding tube), regardless of whether affixed directly tothe monochromators entrance slit, to the end of a fibre opticbundle, or to the aperture of an integrati
32、ng sphere, shall not beperformed unless the radiometer being calibrated is a truepyrheliometer (that is, unless it possesses a view-limitingdevice having the approximate optical constants of the spec-troradiometers pyrheliometer-comparison tube).4.5 Spectroradiometric measurements performed usingsou
33、rce optics other than the integrating sphere or the “stan-dard” pyrheliometer comparison tube, shall be agreed upon inadvance between all involved parties.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM
34、Standards volume information, refer to the standards Document Summary page onthe ASTM website.3Tetrafluoroethylene such as a special grade of Teflont or an equivalentmaterial, has been found suitable.G1300624.6 Calibration measurements that meet the requirements ofthis test method are traceable to a
35、 national metrologicallaboratory that has participated in intercomparisons of stan-dards of spectral irradiance, largely through the traceability ofthe standard lamps and associated power supplies employed tocalibrate the spectroradiometer.4.7 The accuracy of calibration measurements performedemploy
36、ing a spectroradiometer is dependent on, among otherrequirements, the degree to which the temperature of themechanical components of the monochromator are maintainedduring field measurements in relation to those that prevailedduring calibration of the spectroradiometer.NOTE 7This requirement is cove
37、red in detail in an ASTM standardunder development in Subcommittee G03.09 on Radiometry.5. Apparatus5.1 Reference Spectroradiometers:5.1.1 The spectroradiometer employed as the referenceradiometer shall, regardless of whether it consists of a scanningor a linear-diode-array monochromator, be calibra
38、ted withinthe last month in accordance with the procedures specified byCIE Publication 634and the manufacturer.5.1.1.1 It is recommended that the reference spectroradiom-eter, or one of its exact type, has been a participatingspectroradiometer in an intercomparison of spectroradiometerseither manage
39、d, sponsored, or sanctioned by a national metro-logical laboratory, or another appropriate body.5.1.1.2 Alternatively, it is recommended that the referencespectroradiometer shall have participated in an intercompari-son by measurement of a reference lamp source that is eithermanaged, sponsored, or s
40、anctioned by a national metrologicallaboratory, or another appropriate body.5.1.2 If a linear diode-array spectroradiometer is used as thereference, it shall possess focusing optics internal to themonochromator and a linear diode array detector with asufficient number of diodes that, together, resul
41、t in a resolvingpower of 1 nm or less. The monochromators dispersiveelement shall be a holographic grating, and the spectroradiom-eters acceptance optics shall consist of either an integratingsphere with appropriately sized and oriented light entranceport, or a shaped translucent diffuser plate (suc
42、h as a TFE3orAl2O3wafer) whose deviation from true cosine response issmall and known. A further requirement is that the stray lightrejection be determined for any diode-array spectroradiometersused to perform this test method and that it be 105or greater inthe spectral region for which calibration i
43、s required.5.1.2.1 A diode-array spectroradiometer shall not be used asthe reference instrument below 300-nm wavelength. Further,when used in the wavelength region between 300 and 320-nmwavelength, evidence shall be presented with the calibrationreports, or certificates, showing that the stray light
44、 has beeneliminated by a combination of internal baffeling, merging oftwo determinations in which the wavelength region below320-nm is measured employing secondary filters to reject allwavelengths longer than 320 nm, other techniques, or combi-nations of these.5.1.3 When an integrating sphere is use
45、d, the exit port (tothe monochromator) and entrance port (that represents thereceiver) should be oriented 90 to each other and the sphereshould be equipped with a baffle to occlude all light that mightreach the exit directly from the entrance port.5.1.4 When a pyrheliometer-comparison tube, or other
46、view-limiting device, is used for the purpose of calibrating, forexample, ultraviolet pyrheliometers, the pyrheliometer-comparison tube should ideally be affixed to the entrance portof the integrating sphere such that the spheres entrance portbecomes the aperture stop of the view-limiting device. Un
47、dermost circumstances, the pyrheliometer comparison tube shouldpossess the optical geometry defined by the World Meteroro-logical Organization, the principal one being a 5.6 field ofview.NOTE 8When the spheres entrance port is the occluders aperturestop, no calibration of the spectroradiometer is re
48、quired independent of thecalibration with only the integrating sphere in place. If the occludersaperture stop is integral with the occluder and of different smallerdimension than the spheres entrance port, the spectroradiometer must becalibrated with the occluder attached to the integrating sphere .
49、 resultingin greater uncertainties and the possibilities of significant errors.5.2 Computational FacilitiesThe computer-based compu-tational facilities used to import the raw data with respect towavelength and intensity should be capable of providinganalyzed spectral irradiance information integrated across anywavelength band chosen.5.3 Instrument Mounts:5.3.1 Equatorial MountAn altazimuthal or equatorial,follow-the sun mount that is equipped with a platform onwhich the spectroradiometer is mounted is required for allhemispherical normal-incident and di
