1、Designation: E1862 97 (Reapproved 2010)Standard Test Methods forMeasuring and Compensating for Reflected TemperatureUsing Infrared Imaging Radiometers1This standard is issued under the fixed designation E1862; the number immediately following the designation indicates the year oforiginal adoption or
2、, 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 These test methods cover procedures for measuring andcompensating for reflected
3、 temperature when measuring thesurface temperature of a specimen with an infrared imagingradiometer.1.2 These test methods may involve use of equipment andmaterials in the presence of heated or electrically energizedequipment, or both.1.3 This standard does not purport to address all of thesafety co
4、ncerns, 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:2E1316 Terminology for Nondestructive
5、Examinations3. Terminology3.1 Definitions:3.1.1 diffuse reflector, na surface that produces a diffuseimage of a reflected source.3.1.2 infrared thermographer, nthe person using an infra-red imaging radiometer.3.1.3 infrared reflector, na material with a reflectance asclose as possible to 1.00.3.1.4
6、reflected temperature, nthe temperature of the en-ergy incident upon and reflected from the measurement surfaceof a specimen.3.1.5 specular reflector, na surface that produces a directimage of a reflected source.3.2 See also Terminology E1316.4. Summary of Test Methods4.1 Two test methods are given
7、for measuring the reflectedtemperature of a specimen, the Reflector Method and theDirect Method.4.2 A test method is also given for compensating for theerror produced by reflected temperature using the computerbuilt into an infrared imaging radiometer.5. Significance and Use5.1 The infrared energy t
8、hat is reflected by a specimen cancause measurement errors for an infrared thermographer mea-suring its surface temperature. Two test methods are providedfor measuring and compensating for this reflected temperatureerror source, the Reflector Method and the Direct Method.5.2 These test methods can b
9、e used in the field or laboratoryusing commonly available materials.5.3 These test methods can be used with any infraredradiometers that have the required computer capabilities.6. Interferences6.1 Reflector Method:6.1.1 This test method uses an infrared reflector with anassumed reflectance of 1.00,
10、which is an ideal property. Errorscan be minimized by using a reflector having a reflectance asclose as possible to 1.00.6.1.2 Specimens vary in that they can be diffuse or spectralreflectors, or both. Use of an infrared reflector with reflectanceproperties as close as possible to those of the speci
11、men willreduce errors.6.2 Direct Method:6.2.1 The Direct Method usually does not account for theheat from the infrared thermographers body as a source ofreflected temperature. If this heat source creates a significanterror, use the Reflector Method.6.3 Reflected temperature errors produced by a poin
12、tsource, such as the sun or a lamp, are difficult to measureaccurately. These error sources can often be avoided by movingthe infrared imaging radiometers position and angle relative tothe specimen.1These test methods are under the jurisdiction of ASTM Committee E07 onNondestructive Testing and are
13、the direct responsibility of Subcommittee E07.10 onSpecialized NDT Methods.Current edition approved May 1, 2010. Published March 2011. Originallyapproved in 1997. Last previous edition approved in 2002 as E1862 - 97(2002)1.DOI:10.1520/E1862-97R10.2For referenced ASTM standards, visit the ASTM websit
14、e, 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 19428-2959, United States
15、.6.4 The measured reflected temperature of a specimen maybe specific to the waveband of the infrared imaging radiometerused. Therefore, the infrared imaging radiometers wavebandshould be noted with the measured value.6.5 The significance of the error contributed by reflectedtemperature can be estima
16、ted by shielding the specimen fromvarious angles and observing any changes in the thermalimage.6.6 The error caused by reflected temperature can be re-duced by shielding the specimen from the source of thereflection.7. Apparatus7.1 Calibrated Infrared Imaging Radiometer, with a built-incomputer with
17、 the capability to measure temperatures with thecomputers emissivity control set to 1.00.7.2 Tripod, or device to support the infrared imaging radi-ometer.7.3 Infrared ReflectorThe reflector method also requiresan infrared reflector made from a piece of metal whosereflectance is as close as possible
18、 to 1.00. Examples are acrumpled and re-flattened piece of aluminum foil placed shinyside up on a piece of cardboard, or a flat piece of metal withdiffuse or spectral reflection characteristics, or both, similar tothose of the specimen.8. Procedure8.1 Reflector Method:8.1.1 Set the infrared imaging
19、radiometers emissivity con-trol to 1.00.8.1.2 Place the infrared imaging radiometer on the tripod orsupport device at the desired location and distance from thespecimen.8.1.3 Point the infrared imaging radiometer at the specimenand focus on the portion of the specimen where the reflectedtemperature
20、is to be measured.8.1.4 Place the infrared reflector in front of, and parallel to,the specimen (see Fig. 1). Maintain a safe working distancefrom any heated, electrically energized or otherwise potentiallydangerous targets.8.1.5 Without moving the imager and using an appropriatemeasurement function
21、(such as spot temperature, cross hairs orisotherms), measure and record the apparent surface tempera-ture of the reflector reported by the radiometers computer.This is the reflected temperature of this specimen when viewedfrom the position indicated in 8.1.2.8.1.6 Repeat 8.1.1-8.1.5 a minimum of thr
22、ee times andaverage the temperatures to yield an average reflected tempera-ture.8.2 Direct Method:8.2.1 Set the infrared imaging radiometers emissivity con-trol to 1.00.8.2.2 Place the infrared imaging radiometer on the tripod orsupport device at the desired location and distance from thespecimen.8.
23、2.3 Point the infrared imaging radiometer at the specimenand focus on the portion where the reflected temperature is tobe measured.8.2.4 Estimate or measure the angle of reflection and theangle of incidence when viewing the specimen with theinfrared imaging radiometer from this location (see Fig. 2)
24、.8.2.5 Remove the infrared imaging radiometer from thetripod and position it so that it is pointing away from thespecimen and in the same direction as the angle of reflection(see Fig. 3, Line A). Using an appropriate measurementfunction (such as spot temperature, cross hairs or isotherms),measure an
25、d record the apparent temperature reported by theradiometers computer. This is the reflected temperature of thisspecimen when viewed from the position indicated in 8.2.2.8.2.6 If the specimen surface is a diffuse reflector, point theradiometer at a variety of locations within 45 of both sides ofthe
26、angle of incidence and average the reported temperatures.This average is the reflected temperature of the specimen whenviewing the specimen from the position indicated in 8.2.2.8.2.7 Repeat 8.2.1-8.2.6 a minimum of three times andaverage the temperatures to yield an average reflected tempera-ture.8.
27、3 Compensate for the reflected temperature by enteringthe average reflected temperature in the reflected temperatureinput of the radiometers computer, commonly referred to as“TAM,” “Ambient Temperature,” “Amb Temp” or “ReflectedBackground.”9. Precision and Bias9.1 PrecisionAn interlaboratory test pr
28、ogram is not prac-tical here because of the nature of the specimens. However, aFIG. 1 Reflector MethodFIG. 2 Estimating the Angle of Reflection and IncidenceE1862 97 (2010)2measure of the precision of the test methods can be inferredfrom the results of the replicate tests specified in 8.1.6 and8.2.7
29、.9.2 BiasThese test methods for measuring reflected tem-perature have no bias because the values of reflected tempera-ture are defined only in terms of the test methods.10. Keywords10.1 imaging; infrared; infrared examination; infrared re-flector; infrared testing; infrared thermography; nondestruct
30、ivetesting; radiometry; reflected temperature; temperature com-pensation; temperature measurementASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determi
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33、our 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,United States. Individual reprints (si
34、ngle 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 ASTM website (www.astm.org/COPYRIGHT/).FIG. 3 Direct MethodE1862 97 (2010)3
