1、Designation: E1390 12 (Reapproved 2016)Standard Specification forIlluminators Used for Viewing Industrial Radiographs1This standard is issued under the fixed designation E1390; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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 The function of the illuminator is to provide sufficientillumination and viewing capabilities for the purpose of
3、 iden-tification and interpretation of radiographic images. This speci-fication provides the recommended minimum requirements forIndustrial Radiographic Illuminators used for viewing indus-trial radiographic films using transmitted light sources.1.2 The illuminator has to ensure the same safety forp
4、ersonnel, or users of any electric apparatus, as specified byelectrical standards applicable in the country in which theilluminator is used.1.3 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 t
5、o establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 Values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation only.2. Referenced Documents2.1 ASTM Standards:2E1
6、316 Terminology for Nondestructive Examinations3. Terminology3.1 Definitions:3.1.1 diffusing screenthe screen that scatters the light suchthat the light appears the same brightness from any viewingangle.3.1.2 viewing screenthe port through which the light isprojected.3.2 For additional definitions o
7、f terms used in thisspecification, see Terminology E1316.4. Ordering Information4.1 This specification is intended to be used by the manu-facturers and purchasers of radiographic illuminators.Requirements, if imposed on manufacturers, should be estab-lished by contractual agreement or appropriate pu
8、rchase docu-ment.5. Materials and Manufacture5.1 GeneralThe illuminator shall consist of a housingwith one or more of the sides containing a viewing screenilluminated from the inside of the housing. The viewing screenmay also be the diffusing screen. There shall be thermalprotection to prevent overh
9、eating, and subsequent damage tothe radiographs placed on the viewing screen. The housing orsystem may or may not require ventilation. A rheostat orsuitable electrical circuit shall be provided to vary the lightintensity.6. Physical Properties6.1 GeneralThe illuminator shall be manufactured ofmateri
10、als deemed suitable to withstand the environmentalconditions encountered under normal operating conditions.6.2 Viewing ScreenThe viewing screen shall be easy toclean and made of material which is resistant to scratches. Thesize of the screen shall allow the user to view the radiographwithout excessi
11、ve glare. If the illuminator is to be used forviewing radiographs of various sizes, masks of various sizesand configurations should be provided. Alternately, an adjust-able aperture may be used.6.3 Color of LightThe color of the light used to illuminatethe radiograph shall be white, that is, color t
12、emperaturebetween 5000 and 6250K. However, illuminators using non-white or “colored” light may be used if they have beenrecommended by the film manufacturers.6.4 Diffusing ScreenIf the illuminator has a diffusingscreen, the light shall be sufficiently divergent in accordancewith 7.2.6.5 HousingThe e
13、xternal housing shall be constructed insuch a manner that no disturbing light hinders the viewing ofthe radiographs.6.6 Anti-Glare DeviceThe illuminator shall be fitted withan anti-glare switch or device that minimizes the probability of1This specification is under the jurisdiction of ASTM Committee
14、 E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology (X and Gamma) Method.Current edition approved Dec. 1, 2016. Published December 2016. Originallyapproved in 1990. Last previous edition approved in 2012 as E1390 - 12. DOI:10.1520/E1390-12R16.2For refere
15、nced 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 website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
16、onshohocken, PA 19428-2959. United States1the operator being subjected to excessive glare when theradiograph is removed. This switch or device may be manual orautomatic.6.7 Illuminators Used for Viewing “Wet” RadiographsIlluminators manufactured for use in viewing “wet” radio-graphs shall be manufac
17、tured to prevent the penetration ofliquid into internal electrical components in such a manner thatsafe operation of the unit would be compromised.7. Performance Requirements7.1 Maximum Luminance outputThe luminance of thetransmitted light shall not be less than 30 candelas per squaremetre for film
18、densities equal to or less than 2.5 optical densityand not less than 10 candelas per square metre for filmdensities greater than 2.5 optical density.7.2 Divergence and Diffusion of LightIf the illuminatorhas a diffusing screen, the light shall be sufficiently divergentso that both eyes of the observ
19、er receive rays from all parts ofthe screen. The divergence factor shall exceed 0.7.7.3 The viewing screen shall be uniformly illuminated withthe uniformity factor being higher than 0.5.7.4 Appropriate precautions shall be taken by the manufac-turer to ensure that temperature of the housing does not
20、 exceed60C (140F) at the usual contact surfaces after one hour ofoperation at a 50 % duty cycle.7.5 A radiograph having a density of 2.0 optical densitywhen placed onto the illuminator viewing surface shall notwarp or curl after one minute of continuous viewing time andone hour of operation of the i
21、lluminator at a 50 % duty cycle.8. Scope8.1 The following tests shall be utilized to verify theperformance requirements specified in 7.1 through 7.3 of thisspecification.8.1.1 Maximum illuminator luminance shall be determinedusing a calibrated photometer placed at the center of theviewing surface, a
22、nd shall be measured in accordance with thedirections specified by the photometers manufacturer.8.1.2 Maximum illuminator luminance measurements are totake place in a room with less than 20 lux (approximately 2footcandles) of background light. Light escaping from theilluminator even when the viewing
23、 screen is completelymasked shall not affect the measurements.8.2 Divergence and Diffusion of LightIf the illuminatorhas a diffusing screen, the light shall be sufficiently divergentso that both eyes of the observer receive rays from all parts ofthe screen. The divergence factor shall exceed 0.7.8.2
24、.1 The luminance shall be measured on a semi-circle, thecenter of which is center of the screen.8.2.2 The diameter of the circle is approximately the sameas the maximum dimension of the screen (the diagonal). Theradius of this semi-circle should be at least 25 cm (10 in.).8.2.3 The luminance is meas
25、ured with the aid of an appro-priate luminance photometer whose sensitive surface is tangentto the curve of the circle (see Fig. 1). These measurements shallbe made at angles of 5 (L5), 20 (L20), and 45 (L45) relativeto the normal (L0) to the diffusing screen. The divergencefactor, , shall be calcul
26、ated according to the followingequation: 5L451L202 L58.3 The viewing screen shall be uniformly illuminated withthe uniformity factor being higher than 0.5, and calculated inthe following manner:8.3.1 The measurements shall be made with the aid of anillumination photometer or other suitable instrumen
27、t.8.3.2 If the screen is rectangular, it shall be divided intosquares, each side of the squares measuring 3.5 cm, theluminance of each being measured separately. If the screen iscircular, the same basic procedure shall be followed. In bothcases, the network of the squares shall be so arranged that t
28、hemiddle square is centered in the middle of the screen.8.3.3 The average of the four highest and the average of thefour lowest results shall be found, which give the averagearithmetical values of the luminance Lmaxand Lmin. Theuniformity factor g shall then be calculated according to theformula: 5L
29、minLmax9. Certification9.1 The manufacturer is responsible for certifying that theilluminator conforms to the requirements of this specificationprior to shipping to customer.9.2 At the request of the customer, the manufacturer of theilluminator shall provide a written statement indicating confor-man
30、ce to the requirements of this specification and test resultsif requested.10. Product Marking10.1 Each illuminator will have the following informationpermanently affixed by the manufacturer:10.1.1 Nominal operating voltage or permissible voltagerange.10.1.2 Nominal line frequency or permissible freq
31、uencyrange.FIG. 1 Measurement Angles of Diversion and Dispersion of LightE1390 12 (2016)210.1.3 Whether direct, alternating current, or both may beused.10.1.4 Whether designed for use with “wet” film viewing.10.1.5 Nominal power consumption.10.1.6 Maximum brightness in candelas per square metre asca
32、lculated during factory acceptance tests.10.1.7 Lamp type.11. Packaging and Package Marking11.1 Each illuminator will be provided with operatinginstructions that address the following:11.1.1 Safety precautions to be expected during the normaloperating conditions.11.1.2 Operating conditions.11.1.3 In
33、structions for mounting and replacements of lampsand screens.11.1.4 Care and recommended maintenance procedures.11.1.5 Replacement lamp and screen identification and sup-plier contact information.12. Quality Assurance12.1 The manufacturer is responsible for testing and certi-fying that the illuminat
34、or conforms to the requirements of thisspecification prior to shipping to customer.13. Keywords13.1 illuminator; luminance; radiographASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standa
35、rd are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif
36、 not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, whi
37、ch you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,U
38、nited States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 12 (2016)3
