ASTM_E_1135_-_12.pdf

Designation:E113512Standard Test Method forComparing the Brightness of Fluorescent Penetrants1This standard is issued under the fixed designation E1135;the number immediately following the designation indicates the year 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.Scope*1.1 This test method describes the techniques for comparingthe brightness of the penetrants used in the fluorescent dyepenetrant process.This comparison is performed under con-trolled conditions which eliminate most of the variables presentin actual penetrant examination.Thus,the brightness factor isisolated and is measured independently of the other factorswhich affect the performance of a penetrant system.1.2 The brightness of a penetrant indication is dependent onthe developer with which it is used.This test method however,measures the brightness of a penetrant on a convenient filterpaper substrate which serves as a substitute for the developer.1.3 The brightness measurement obtained is color-correctedto approximate the color response of the average human eye.Since most examination is done by human eyes,this numberhas more practical value than a measurement in units of energyemitted.Also,the comparisons are expressed as a percentage ofsome chosen standard penetrant because no absolute system ofmeasurement exists at this time.1.4 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 safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1316 Terminology for Nondestructive Examinations3.Terminology3.1 Definitions:3.1.1 Definitions of terms applicable to this test method maybe found in Terminology E1316.4.Summary of Test Method4.1 Simulated indications are prepared by impregnatingfilter paper with a specified quantity of the penetrant under test.The samples and similarly prepared standards are then mea-sured in a fluorometer equipped to excite the penetrant withnear ultraviolet(black)light and respond to color approxi-mately as does the human eye under the conditions encoun-tered during a normal examination.The fluorometer must beequipped with a special sample holder to accept the samplesemployed.4.2 The sample preparation is not indicative of the totalsystem performance but is convenient as a lot acceptance test.A known amount of penetrant is diluted with a specifiedamount of a volatile solvent,pieces of filter paper are soaked inthe mixture,the paper is dried under specified conditions atroom temperature,placed in the sample holder,and measuredwith the fluorometer.5.Significance and Use5.1 The penetrant is one of the major components of thefluorescent penetrant process,and very influential in the degreeof performance attained by a given system or group ofmaterials.The penetrant must enter the discontinuity,beremoved from the part surface but not from the discontinuity,be brought out of the discontinuity by the developer,and finallyviewed and detected by the inspector.If all processing param-eters are optimized for the parts being examined and theexamination materials in use,the intrinsic brightness of thepenetrant becomes the factor which governs the sensitivity ofthe system.5.2 Because the eye responds logarithmically rather thanlinearly to changes of brightness,differences in brightnessmust be fairly large to be significant.Differences of 25%areobvious,12%noticeable,and 6%detectable by the eye.Experts may sometimes detect 3%differences,but these arenot usually significant to the average observer.5.3 The significance of the results also depends on thedeviation between readings on the same material sample.Different samples,even when prepared out of the same initialquantity of penetrant will not exactly reproduce readings.1This 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 June 15,2012.Published July 2012.Originallyapproved in 1986.Last previous edition approved in 2008 as E1135 97(2008)1.DOI:10.1520/E1135-12.2For 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 website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 These differences occur because of paper differences andpenetrant migration on the pa