1、Designation: E2297 04 (Reapproved 2010)Standard Guide forUse of UV-A and Visible Light Sources and Meters used inthe Liquid Penetrant and Magnetic Particle Methods1This standard is issued under the fixed designation E2297; the number immediately following the designation indicates the year oforigina
2、l adoption or, in the case 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. Scope1.1 This guide describes the use of UV-A/Visible lightsources and mete
3、rs used for the examination of materials by theliquid penetrant and magnetic particle processes. This guidemay be used to help support the needs for appropriate lightintensities and light measurement.1.2 This guide also provides a reference:1.2.1 To assist in the selection of light sources and meter
4、sthat meet the applicable specifications or standards.1.2.2 For use in the preparation of internal documentationdealing with liquid penetrant or magnetic particle examinationof materials and parts.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are ma
5、thematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard1.4 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 sa
6、fety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E165 Practice for Liquid Penetrant Examination for GeneralIndustryE709 Guide for Magnetic Particle TestingE1208 Practice for Fluorescent Liquid Penetrant Testi
7、ngUsing the Lipophilic Post-Emulsification ProcessE1209 Practice for Fluorescent Liquid Penetrant TestingUsing the Water-Washable ProcessE1210 Practice for Fluorescent Liquid Penetrant TestingUsing the Hydrophilic Post-Emulsification ProcessE1219 Practice for Fluorescent Liquid Penetrant TestingUsin
8、g the Solvent-Removable ProcessE1220 Practice for Visible Penetrant Testing Using Solvent-Removable ProcessE1316 Terminology for Nondestructive ExaminationsE1417 Practice for Liquid Penetrant TestingE1418 Practice for Visible Penetrant Testing Using theWater-Washable ProcessE1444 Practice for Magnet
9、ic Particle Testing3. Terminology3.1 The definitions that appear in E1316, relating to UV-Aradiation and visible light used in liquid penetrant and mag-netic particle examinations, shall apply to the terms used in thisguide.4. Summary of Guide4.1 This guide shows how the proper meter is correctly us
10、edto determine if adequate light levels (UV-A and/or visible) areavailable for use while conducting a liquid penetrant ormagnetic particle examination.5. Significance and Use5.1 UV-A and Visible light sources are used to provideadequate light levels for liquid penetrant and magnetic particleexaminat
11、ion. Light meters are used to verify that specified lightlevels are available.5.2 Fluorescence is produced by irradiating the fluorescentdyes/pigments with UV-A radiation. The fluorescent dyes/pigments absorb the energy from the UV-A radiation andre-emit light energy in the visible spectrum. This en
12、ergytransfer allows fluorescence to be observed by the human eye.5.3 High Intensity UV-A light sources produce light inten-sity greater than 10,000 W/cm2at 38.1 cm (15 in.).1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subc
13、ommittee E07.03 on LiquidPenetrant and Magnetic Particle Methods.Current edition approved Aug. 1, 2010. Published November 2010. Originallyapproved 2004 as E2297 - 04. DOI: 10.1520/E2297-04R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
14、rviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Equipment6.1 Ultraviolet (UV)/Visible Light Spectr
15、um6.1.1 The most common UV sources emit radiation in theultraviolet section of the electromagnetic spectrum (between180 nm (1800 ) to 400 nm (4000 ). Ultraviolet radiation isa part of the electromagnetic radiation spectrum between theviolet/blue color of the visible spectrum and the weak X-rayspectr
16、um. (See Fig. 1.)6.1.2 The UV-A range (used for fluorescent liquid penetrantand fluorescent magnetic particle examinations) is consideredto be between 320 nm (3200 ) and 400 nm (4000 ). TheUV-B range (medium UV) is considered to be between 280 nm(2800 ) and 320 nm (3200 ). The UV-C range (short UV)
17、isconsidered to be between 180 nm (1800 ) and 280 nm (2800). The visible spectrum is considered to be between 400 nm(4000 ) and 760 nm (7600 ).6.2 Mercury Vapor UV-A Sources6.2.1 Most UV-A sources used in fluorescent NDT utilize alamp containing a mercury-gas plasma that emits radiationspecific to t
18、he mercury atomic transition spectrum. There areseveral discrete lines of the mercury spectrum in the ultravioletsection of the electromagnetic spectrum (between 180 nm(1800 ) and 400 nm (4000 ). The irradiance output isdependent on the gas pressure and the amount of mercurycontent. Higher values of
19、 gas pressure and mercury contentresult in significant increase in its UV emission.6.2.2 UV-A sources used for NDT, employ appropriatefilters, either internal or external to the light source to minimizethe visible light output (400 nm (4000 ) to 760 nm (7600 )that is detrimental to the fluorescent i
20、nspection process. Thesefilters should also block harmful radiation below 320 nm (3200).6.2.3 UV-A sources are generally low or medium pressurevapor sources. Low pressure lamps are coated with a specialphosphor in order to maximize the UV-A output. Mediumpressure lamps do not have phosphor coatings
21、but operate athigher electrical power levels, resulting in significantly higherUV-A output.6.2.4 Typically, low pressure lamps (tubes) are used in washstations or for general UV-A lighting in the inspection room.Medium pressure lamps are used in fluorescent inspectionstations. A well designed medium
22、 pressure UV-A lamp shouldemit less that 0.25 % to 1 % of its total intensity under 320 nm(3200 ) and above 400 nm (4000 ). A UV-A bulb based onthe American National Standards Institutes Specification H 44GS-R100 is a 100 watt mercury-vapor bulb in the Par 38configuration and normally using a Kopp 1
23、0413UV filter.Other newer lamps using the same bulb but with the Kopp10713UV filter or bulbs based on the Philips HPW 125-wattbulb4will not differ greatly in UV-A output, but in general willproduce more visible light in the blue/violet part of thespectrum. (WarningCertain high-intensity UV-A lightso
24、urces may emit unacceptable amounts of visible light, whichwill cause fluorescent indications to disappear. Care should betaken to use only bulbs certified by the supplier to be suitablefor such examination purposes.)NOTE 1The Philips HPW 125-watt bulb has been restricted from usein the inspection s
25、tation by many aerospace companies.6.3 UV-A Borescope, Fiberscope, Videoimagescope andSpecial UV-A Light Source Systems6.3.1 Borescopes, fiberscopes and videoimagescopes arethin rigid or flexible tubular optical telescopes. They are nondestructive inspection quality control instruments for the visua
26、ldetection of surface discontinuities in small bores, castings,pipe interiors, and on internal components of complex machin-ery.6.3.2 The conventional optical glass fiber used as a lightguide in borescopes, fiberscopes and videoimagescopes may bea poor transmitter of UV-A radiation. These fibers tra
27、nsmitwhite light in the 450 nm (4500 ) to 760 nm (7600 ) range,3Kopp 1041 UV and Kopp 1071 UV are registered trademarks of Kopp GlassInc., Pittsburgh, PA.4Philips HPW 125 watt is a registered trademark of Philips Lighting Co.,Somerset, NJ.FIG. 1 The Electromagnetic Radiation SpectrumE2297 04 (2010)2
28、but do not effectively transmit light in the 350 nm (3500 ) to380 nm (3800 ) range.6.3.3 Three non traditional light guide materials for im-proved UV-A transmission in borescopes, fiberscopes orvideoimagescopes, are liquid light guides, silica or quartzfibers, or special new glass fibers.6.3.3.1 Sil
29、ica or quartz fibers are good transmitters of UV-Aenergy, but are brittle and cannot be bent into a tight radiuswithout breaking, nor can they accommodate the punishingstresses of repeated scope articulation.6.3.3.2 Liquid light guides are very effective transmitters ofUV-A, but have minimum diamete
30、r limitations at 2.5 mm andalso exhibit problems with collapsing, kinking or loss of fluids.6.3.3.3 Aspecial glass fiber configuration offers the best UVperformance plus durability. Special glass fiber light bundlescombine high UV output with the necessary flexibility anddurability required in these
31、 scopes.6.4 UV-A Pencil Lamps6.4.1 The pencil lamp is one of the smallest sources ofUV-A radiation. It is generally a lamp coated with conversionphosphors that absorb the 254 nm (2540 ) line of energy andconvert this energy into a band peaking at 365 nm (3650 ).The lamp may be encased in a tubular g
32、lass filter that absorbsvisible light while transmitting maximum ultraviolet intensity.The pencil lamp is useful for fluorescent analysis and boro-scopic inspection in inaccessible locations.NOTE 2Pencil Lamps produce low levels of UV-A radiation.6.4.2 As with all metal vapor discharge lamps, the ou
33、tput ofa quartz pencil lamp slowly decreases throughout its life. Theactual useful life will be dependent upon dust and othercontaminants collecting on the lamp and its reflecting andtransmissive elements can cause more UV-A intensity loss atthe irradiated surface than the age of the lamp.6.5 High I
34、ntensity UV-A Light Sources There are two typesof high intensity UV-A sources; 1) a UV flood fixture and 2) ahand held ultra-high intensity micro discharge lamp (MDL).6.5.1 The high intensity flood fixture normally uses a highwattage metal halide bulb. This lamp will also contain sometype of special
35、ly coated parabolic reflector. The high intensityof this lamp will produce a great deal of heat, so some type ofcooling fan must be used.6.5.2 The MDL lamp uses a 35 watt metal halide bulb andtherefore produces very little heat. Normally, a cooling fan isnot required. (WarningWhen a high intensity U
36、V-A lamp(light sources that produce light intensity greater than 10,000W/cm2at 38.1 cm (15 in.) is used for inspection, care mustbe exercised to prevent the UV fading of indications and thatthe excess blue light that is produced, does not mask blue/whiteindications.)NOTE 3ASTM E1208, E1209, E1210, E
37、1219, E1417, and E1444provide UV-A light requirements for fluorescent magnetic particle andfluorescent penetrant inspection processes.6.6 Visible Light Sources6.6.1 Visible light sources produce radiation in the 400 nm(4000 ) to 760 nm (7600 ) region in the electromagneticspectrum. They have various
38、 intensities and different colorresponses that are easily observed by the human eye. Thevisible energy spectrum is easily absorbed by the eyesphotoreceptors.6.6.2 These photoreceptors are of two types, cones and rods.6.6.2.1 Rods are highly sensitive to low intensities of lightand contain only a sin
39、gle photopigment and is unable todiscriminate color. The eye response under low intensitylighting is referred to as scotopic and uses rod photoreceptors.6.6.2.2 Cone photoreceptors respond to higher light inten-sities and are referred to as photopic. The cones are composedof three different photopig
40、ments that are able to discriminatecolors.NOTE 4ASTM E1220, E1417, E1418, and E1444 provide visiblelight requirements for magnetic particle and penetrant examination.6.7 Light Meters6.7.1 UV-A Light Intensity Meter:Radiant energy is a physical quantity that can be measureddirectly in the laboratory
41、by several types of optical radiationdetectors; such as thermopiles, bolometers, pyroelectric instru-ments, and radiometric meters. All UV measuring devices areselective, and their sensitivity depends upon the wavelength ofthe radiation being measured.6.7.1.1 The thermopile uses two dissimilar metal
42、s anddepends on electromotive force (EMF) to measure UV radia-tion.6.7.1.2 The bolometer is a wheatstone bridge, one arm ofwhich is heated by the optical radiation to produce a responseto UV radiation.6.7.1.3 Even though the above two instruments are verysensitive, they are extremely delicate and th
43、eir use is restrictedto the laboratory.6.7.2 The most practical measurement tool suitable for NDTfluorescent inspection is the radiometer. There are two types ofradiometers, one with a digital and one with an analogresponse. The digital and analog meters must have a filtersystem to produce the maxim
44、um response at 365 nm (3650 )(the wavelength used by magnetic particle and penetrantfluorescent dyes and pigments to produce fluorescence).NOTE 5The radiometer measures UV-A light intensity in units ofW/cm2.6.7.2.1 The digital meter is usually the meter of choicebecause of its ease of use. Another a
45、dvantage is that the digitalmeter can measure high and low intensities of UV-A radiationwithout using screens or a mask to restrict the amount of UV-Aradiation impinging on the sensor.6.7.2.2 Digital meters generally have a sensor approxi-mately 1 cm2, and contain specific optical components thatdef
46、ine the spectral range and convert the radiation into electri-cal current. The current is then processed by the instrumentssolid-state electronics and displayed digitally.6.7.3 Visible Light Meters:Just like UV-A meters, there are two types of visible lightmeters, digital and analog. Visible light m
47、eters must havefilters to limit the meter response to the 400 nm (4000 ) to760 nm (7600 ) region in the electromagnetic spectrum.Visible light meters use silicon photodiodes to measure lightintensity. Unlike UV-A meters, visible light meters offer aE2297 04 (2010)3choice of response in either lux or
48、 foot-candles (1 foot candleequals 10.76 lux). Meter response in foot candles is generallyused for NDT inspections in the United States. (WarningMany meters purchased over the counter, do not have theproper filters to measure light from 400 nm (4000 ) to 760 nm(7600 ).)7. UV-A/Visible Light Measurem
49、ent7.1 UV-A light measurement may require two types ofmeasurement for fluorescent examinations.7.1.1 The first is to measure the UV-Aradiation produced bythe light source at a specified distance.7.1.1.1 This measurement is performed for two reasons. Thefirst is to develop a history on the light source and the secondis to assure that the light output is in compliance with thespecification in use.7.1.1.2 If the distance is controlled, then the intensity of thelamp can be observed and the degradation of the bulb can berecorded to assure th
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