1、Designation: E3022 15Standard Practice forMeasurement of Emission Characteristics andRequirements for LED UV-A Lamps Used in FluorescentPenetrant and Magnetic Particle Testing1This standard is issued under the fixed designation E3022; the number immediately following the designation indicates the ye
2、ar oforiginal 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 practice covers the procedures for testing theper
3、formance of ultraviolet A (UV-A), light emitting diode(LED) lamps used in fluorescent penetrant and fluorescentmagnetic particle testing (see Guides E709 and E2297, andPractices E165/E165M, E1208, E1209, E1210, E1219, E1417/E1417M and E1444).2This specification also includes report-ing and performan
4、ce requirements for UV-A LED lamps.1.2 These tests are intended to be performed only by themanufacturer to certify performance of specific lamp models(housing, filter, diodes, electronic circuit design, opticalelements, cooling system, and power supply combination) andalso includes limited acceptanc
5、e tests for individual lampsdelivered to the user. This test procedure is not intended to beutilized by the end user.1.3 This practice is only applicable for UV-A LED lampsused in the examination process. This practice is not applicableto mercury vapor, gas-discharge, arc or luminescent (fluores-cen
6、t) lamps or light guides (for example, borescope lightsources).1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does
7、 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 Documents2.1 ASTM Stand
8、ards:3E165/E165M Practice for Liquid Penetrant Examination forGeneral IndustryE709 Guide for Magnetic Particle TestingE1208 Practice for Fluorescent Liquid Penetrant TestingUsing the Lipophilic Post-Emulsification ProcessE1209 Practice for Fluorescent Liquid Penetrant TestingUsing the Water-Washable
9、 ProcessE1210 Practice for Fluorescent Liquid Penetrant TestingUsing the Hydrophilic Post-Emulsification ProcessE1219 Practice for Fluorescent Liquid Penetrant TestingUsing the Solvent-Removable ProcessE1316 Terminology for Nondestructive ExaminationsE1348 Test Method for Transmittance and Color by
10、Spec-trophotometry Using Hemispherical GeometryE1417/E1417M Practice for Liquid Penetrant TestingE1444 Practice for Magnetic Particle TestingE2297 Guide for Use of UV-Aand Visible Light Sources andMeters used in the Liquid Penetrant and Magnetic ParticleMethods2.2 Other Standards:4ANSI/ISO/IEC 17025
11、 General Requirements for the Com-petence of Testing and Calibration LaboratoriesANSI/NCSL Z540.3 Requirements for the Calibration ofMeasuring and Test Equipment3. Terminology3.1 DefinitionsGeneral terms pertaining to ultraviolet A(UV-A) radiation and visible light used in liquid penetrant and1This
12、test method is under the jurisdiction of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.03 onLiquid Penetrant and Magnetic Particle Methods.Current edition approved Sept. 1, 2015. Published September 2015. DOI:10.1520/E3022-152The use of LED lamps fo
13、r penetrant examination may be covered by a patent.Interested parties are invited to submit information regarding the identification ofalternative(s) to this patented item to ASTM International Headquarters. Yourcomments will receive careful consideration at a meeting of the responsibletechnical com
14、mittee, which you may attend.NOTE: ASTM International takes no position respecting the validity of any patentrights asserted in connection with any item mentioned in this standard. Users of thisstandard are expressly advised that determination of the validity of any such patentrights, and the risk o
15、f infringement of such rights, are entirely their ownresponsibility.3For 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 w
16、ebsite.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1magnetic examination are defined in Terminology E131
17、6 andshall apply to the terms used in this practice.3.2 Definitions of Terms Specific to This Standard:3.2.1 battery-powered hand-held lamp, nlamp poweredby a battery used in either stationary or portable applicationswhere line power is not available or convenient.3.2.1.1 DiscussionThese lamps may a
18、lso have the optionto be line-powered (that is, alternating current power supply).Smaller lamps, often referred to as “flashlights” or “torches”are used for portable examination of focused zones and oftenhave a single LED.3.2.2 current ripple, nunwanted residual periodic varia-tion (spikes or surges
19、) of the constant current that drives theLED at a constant power level.3.2.2.1 DiscussionRipple is due to incomplete suppres-sion of DC (peak to peak) variance resulting from the powersupply, stability of regulation circuitry, circuit design, andquality of the electronic components.3.2.3 excitation
20、irradiance, nirradiance calculated in therange of 347 nm and 382 nm. This corresponds to the range ofwavelengths that effectively excite fluorescent penetrant dyes(i.e. greater than 80% of relative peak excitation).3.2.4 irradiance, E, nradiant flux (power) per unit areaincident on a given surface.
21、Typically measured in units ofmicro-watts per square centimeter (W/cm2).3.2.5 lamp model, nA lamp with specific design. Anychange to the lamp design requires a change in modeldesignation and complete qualification of the new model.3.2.6 light-emitting diode, LED, nsolid state electronicdevices consi
22、sting of a semiconductor or semiconductor ele-ments that emit radiation or light when powered by a current.3.2.6.1 DiscussionLEDs emit a relatively narrow band-width spectrum when a specific current flows through the chip.The emitted wavelengths are determined by the semiconductormaterial and the do
23、ping. The intensity and wavelength canchange depending on the current, age, and chip temperature.3.2.7 line-powered lamp, ncorded hand-held or overheadlamps that are line-powered and typically used for stationaryinspections within a controlled production environment.3.2.7.1 DiscussionThese lamps are
24、 used for examinationof both small and large inspection zones and consist of an LEDarray. Overhead lamps are used in a stationary inspection boothto flood the inspection area with UV-A radiation. Handheldlamps are used to flood smaller regions with UV-A radiationand can also be used in portable appl
25、ications where line poweris available.3.2.8 minimum working distance, nthe distance from theinspection surface where the lamp beam profile begins toexhibit non-uniformity.3.2.9 transmittance, ratio of the radiant flux transmittedthrough a body to that incident upon it.4. Significance and Use4.1 UV-A
26、 lamps are used in fluorescent penetrant andmagnetic particle examination processes to excite fluorophores(dyes or pigments) to maximize the contrast and detection ofdiscontinuities. The fluorescent dyes/pigments absorb energyfrom the UV-A radiation and re-emit visible light whenreverting to its gro
27、und state. This excitation energy conversionallows fluorescence to be observed by the human eye.4.2 The emitted spectra of UV-A lamps can greatly affectthe efficiency of dye/pigment fluorescent excitation.4.3 Some high-intensity UV-Alamps can produce irradiancegreater than 10 000 W/cm2at 15 in. (381
28、 mm). All high-intensity UV-A light sources can cause fluorescent dye fadeand increase exposure of the inspectors unprotected eyes andskin to high levels of damaging radiation.4.4 UV-A lamps can emit unwanted visible light and harm-ful UV radiation if not properly filtered. Visible light contami-nat
29、ion above 400 nm can interfere with the inspection processand must be controlled to minimize reflected glare and maxi-mize the contrast of the indication. UV-B and UV-C contami-nation must also be eliminated to prevent exposure to harmfulradiation.4.5 Pulse Width Modulation (PWM) and Pulse Firing (P
30、F)of UV-A LED circuits are not permitted.NOTE 1The ability of existing UV-A radiometers and spectroradiom-eters to accurately measure the irradiance of pulse width modulated orpulsed fired LEDs and the effect of pulsed firing on indication detectabilityis not well understood.5. Classifications5.1 LE
31、D UV-A lamps used for nondestructive testing shallbe of the following types:5.1.1 Type ALine-powered lamps (LED arrays for hand-held and overhead applications) (3.2.5 and 3.2.6).5.1.2 Type BBattery powered hand-held lamps (LED ar-rays for stationary and portable applications) (3.2.1).5.1.3 Type CBat
32、tery powered, handheld lamps (singleLED flashlight or torch for special applications) (3.2.1, Dis-cussion).6. Apparatus6.1 UV-A Radiometer, designed for measuring the irradianceof electromagnetic radiation. UV-A radiometers use a filter andsensor system to produce a bell-shaped (i.e. Gaussian) respo
33、nseat 365 nm (3650 ) or top-hat responsivity centered near365 nm (3650 ). 365 nm (3650 ) is the peak wavelengthwhere most penetrant fluorescent dyes exhibit the greatestfluorescence. Ultraviolet radiometers shall be calibrated inaccordance with ANSI/ISO/IEC 17025, ANSI/NCSL Z540.3,or equivalent. Rad
34、iometers shall be digital and provide aresolution of at least 5 W/cm2. The sensor front end aperturewidth or diameter shall not be greater than 0.5 in. (12.7 mm).NOTE 2 Photometers or visible light meters are not consideredadequate for measuring the visible emission of UV-A lamps whichgenerally have
35、 wavelengths in the 400 nm to 450 nm range.6.2 Spectroradiometer, designed to measure the spectralirradiance and absolute irradiance of electromagnetic emissionsources. Measurement of spectral irradiance requires that suchinstruments be coupled to an integrating sphere or cosinecorrector. This spect
36、roradiometer shall have a resolution of atleast 0.5 nm and a minimum signal-to-noise ratio of 50:1. TheE3022 152system shall be capable of measuring absolute spectral irradi-ance over a minimum range of 300 to 400 nm.6.2.1 The system shall be calibrated using emission sourcereference standards.6.3 S
37、pectrophotometer, designed to measure transmittanceor color coordinates of transmitting specimens. The systemshall be able to perform a measurement of regular spectraltransmittance over a minimum range of 300 to 800 nm.7. Test Requirements7.1 Lamp models used for nondestructive testing (NDT)shall be
38、 tested in accordance with the requirements of Table 1.7.2 LEDs of UV-A Lamps shall be continuously poweredwith the LED drive current exhibiting minimum ripple (see7.6.5). The projected beam shall also not exhibit any perceiv-able variability in projected beam intensity (i.e. strobing,flicker, etc.)
39、 (see 7.4.6).7.3 Maximum IrradianceFixture the UV-A lamp 15 60.25 in (381 6 6 mm) above the surface of a flat, levelworkbench with the projected beam orthogonal to the work-bench surface. The lamp face shall be parallel to the benchwithin 60.25 in. (66 mm). Ensure that battery-powered lamps(Types B
40、and C) are fully charged. Turn on the lamp and allowto stabilize for 5 min. Place a UV-A radiometer, conforming to6.1, on the workbench. Adjust the lamp position such that thefilter of the lamp is 15.0 6 0.25 in. (381 6 12.7 mm) from theradiometer sensor. Scan the radiometer across the projectedbeam
41、 in two orthogonal directions to locate the point ofmaximum irradiance. Record the maximum irradiance value.7.4 Beam Irradiance ProfileAffix the UV-A lamp abovethe surface of a flat, workbench with the projected beamorthogonal to the workbench surface.7.4.1 Type A lamps shall be supplied with altern
42、atingcurrent (ac) power supply at the manufacturers rated powerrequirement. Power conditioning shall be used to ensure astable power supply free of voltage spikes, ripples, or surgesfrom the power supply network.7.4.2 Type B and C lamps shall be powered using a constantvoltage power direct current (
43、DC) supply that provides con-stant DC power at the rated, fully charged battery voltage60.5 V.7.4.3 The UV-A lamp shall be turned on and allowed tostabilize for a minimum of 30 min before taking measure-ments.7.4.4 Place the UV-A radiometer on the workbench. Adjustthe lamp position such that the fac
44、e of the lamp is 15.0 60.25 in. (381 6 6 mm) from the radiometer sensor. Scan theradiometer across the projected beam in two orthogonaldirections to locate the point of maximum irradiance. Recordthis location as the zero point. Using a 0.5-in. (12.7-mm) grid,translate the radiometer across the proje
45、cted beam in 0.5-in.(12.7-mm) increments to generate a two-dimensional (2-D)plot of the beam profile (irradiance versus position). Positionthe radiometer using either an x-y scanner or by manuallyscanning. When manually scanning, use a sheet with 0.5-in.(1.27-cm) or finer squares and record the irra
46、diance value inthe center of each square. The beam irradiance profile shallextend to the point at which the irradiance drops below200 W cm2.7.4.5 Generate and report the 2-D plot of the beam irradi-ance profile (see Fig. 1). Map the range of irradiance from 200to 1000 W/cm2, 1000 to 5000 W/cm2, 5000
47、 to 10 000W/cm2, 10 000 W cm2. Report the minimum beam diam-eter at 1000 and 200 W/cm2.NOTE 3The defined ranges are minimums. Additional ranges arepermitted.7.4.6 During the observations of 7.4.1 through 7.4.5, noteany output power variations indicated by perceived changes inprojected beam intensity
48、, flicker, or strobing. Any variations inobserved beam intensity, flicker, or strobing are unacceptable.7.5 Minimum Working DistanceAffix the lamp approxi-mately 36 in. (900 mm) above a flat, level workbench coveredwith plain white paper. The projected beam shall be orthogonalto the covered workbenc
49、h surface.7.5.1 Measurements shall be performed in a darkened envi-ronment with less than 2 fc (21.5 lux) of ambient light and astable temperature at 77 6 5F (25 63C).7.5.2 Ensure that battery-powered lamps are fully charged.The UV-A lamp shall be turned on and allowed to stabilize fora minimum of 30 min before taking measurements.7.5.3 Observe the beam pattern produced on the paper.Lower the lamp until the beam pattern exhibits visible non-uniformity or reduction in intensity between the individualbeams generated by each LED element or by ir
