1、Designation: E 2297 04Standard 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 E 2297; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, 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.1. Scope1.1 This guide describes the use of UV-A/Visible lightsources and meters used for the
3、 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 metersthat meet the
4、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 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theres
5、ponsibility 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 165 Test Method for Liquid Penetrant ExaminationE 709 Guide for Magnetic Particle Examin
6、ationE 1208 Test Method for Fluorescent Liquid Penetrant Ex-amination Using the Lipophilic Post-Emulsification Pro-cessE 1209 Test Method for Fluorescent Liquid Penetrant Ex-amination Using the Water-Washable ProcessE 1210 Test Method for Fluorescent Liquid Penetrant Ex-amination Using the Hydrophil
7、ic Post-Emulsification Pro-cessE 1219 Test Method for Fluorescent Liquid Penetrant Ex-amination Using the Solvent-Removable ProcessE 1220 Test Method for Visible Penetrant ExaminationUsing the Solvent-Removable ProcessE 1316 Standard Terminology for Nondestructive Examina-tionE 1417 Standard Practic
8、e for Liquid Penetrant ExaminationE 1418 Test Method for Visible Penetrant ExaminationUsing the Water-Washable ProcessE 1444 Standard Practice for Magnetic Particle Examina-tion3. Terminology3.1 The definitions that appear in E 1316, relating to UV-Aradiation and visible light used in liquid penetra
9、nt 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 usedto determine if adequate light levels (UV-A and/or visible) areavailable for use while conducting a liquid penetrant ormagnetic particle ex
10、amination.5. Significance and Use5.1 UV-A and Visible light sources are used to provideadequate light levels for liquid penetrant and magnetic particleexamination. Light meters are used to verify that specified lightlevels are available.5.2 Fluorescence is produced by irradiating the fluorescentdyes
11、/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 energytransfer allows fluorescence to be observed by the human eye.5.3 High Intensity UV-A light sources produce light inten-sity greater than
12、10,000 W/cm2at 38.1 cm 15 in.6. Equipment6.1 Ultraviolet (UV)/Visible Light Spectrum6.1.1 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
13、between the1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.03 on LiquidPenetrant and Magnetic Particle Method.Current edition approved February 1, 2004. Published March 2004.2For referenced ASTM standards, vi
14、sit 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-
15、2959, United States.violet/blue color of the visible spectrum and the weak X-rayspectrum. (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 cons
16、idered to be between 280 nm2800 and 320 nm 3200 . The UV-C range (short UV) isconsidered to be between 180 nm 1800 and 280 nm 2800. The visible spectrum is considered to be between 400 nm4000 and 760 nm 7600 .6.2 Mercury Vapor UV-A Sources6.2.1 Most UV-A sources used in fluorescent NDT utilize alamp
17、 containing a mercury-gas plasma that emits radiationspecific to the mercury atomic transition spectrum. There areseveral discrete lines of the mercury spectrum in the ultravioletsection of the electromagnetic spectrum (between 180 nm1800 and 400 nm 4000 ). The irradiance output isdependent on the g
18、as pressure and the amount of mercurycontent. Higher values of 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 400
19、0 to 760 nm 7600 )that is detrimental to the fluorescent inspection 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 out
20、put. Mediumpressure lamps do not have phosphor coatings 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 i
21、n fluorescent inspectionstations. A well designed medium pressure UV-A lamp shouldemit less that 0.25 % to 1 % of its total intensity under 320 nm3200 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
22、the Par 38configuration and normally using a Kopp 10413UV 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 thesp
23、ectrum. WarningCertain high-intensity UV-A lightsources 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 bul
24、b has been restricted from usein the inspection station 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 ins
25、pection quality control instruments for the visualdetection 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 poo
26、r transmitter of UV-A radiation. These fibers transmitwhite light in the 450 nm 4500 to 760 nm 7600 range,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 orvideoi
27、magescopes, are liquid light guides, silica or quartzfibers, or special new glass fibers.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 Radiatio
28、n SpectrumE22970426.3.3.1 Silica 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 ofU
29、V-A, but have minimum diameter 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 an
30、ddurability required in these 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 b
31、e encased in a tubular glass 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
32、 discharge lamps, the output 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 ag
33、e of the lamp.6.5 High Intensity 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 con
34、tain sometype of specially 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. Warning
35、When a high intensity UV-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 E
36、 1208, E 1209, E 1210, E 1219, E 1417, and E 1444provide 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 nm4000 to 760 nm 7600 region in the electromagneticspectr
37、um. They have various 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 lighta
38、nd contain only a single 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 thr
39、ee different photopigments that are able to discriminatecolors.NOTE 4ASTM E 1220, E 1417, E 1418, and E 1444 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 measureddi
40、rectly in the laboratory 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
41、uses two dissimilar metals 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
42、extremely delicate and their 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 filtersy
43、stem to produce the maximum 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
44、 ease of use. Another advantage 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 opt
45、ical components thatdefine 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:Visible Light Meters Just like UV-A meters, there are twotypes of visible light
46、 meters, digital and analog. Visible lightmeters must have filters to limit the meter response to the 400nm 4000 to 760 nm 7600 region in the electromagneticspectrum. Visible light meters use silicon photodiodes tomeasure light intensity. Unlike UV-A meters, visible lightmeters offer a choice of res
47、ponse in either lux or foot-candles(1 foot candle equals 10.76 lux). Meter response in foot candlesis generally used for NDT inspections in the United States.WarningMany meters purchased over the counter, do nothave the proper filters to measure light from 400 nm 4000 to 760 nm 7600 .E22970437. UV-A
48、/Visible Light Measurement7.1 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 hi
49、story 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 that the bulb is replaced in a timely manner.There are many types of fixtures that may be used to control themeasured distance. The measurement should be taken from theface of the lamp (front of filter/b
