1、Designation: E 1862 97 (Reapproved 2002)e1Standard Test Methods forMeasuring and Compensating for Reflected TemperatureUsing Infrared Imaging Radiometers1This standard is issued under the fixed designation E 1862; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in 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.e1NOTERemoved Footnote 2 in September 2002 since the organization is no longer in busi
3、ness.1. Scope1.1 These test methods cover procedures for measuring andcompensating for reflected 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 electrical
4、ly energizedequipment, or both.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 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitatio
5、ns prior to use.2. Referenced Documents2.1 ASTM Standards:2E 1316 Terminology for Nondestructive 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 radio
6、meter.3.1.3 infrared reflector, na material with a reflectance asclose as possible to 1.00.3.1.4 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 reflecte
7、d source.3.2 See also Terminology E 1316.4. Summary of Test Methods4.1 Two test methods are given 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
8、computerbuilt into an infrared imaging radiometer.5. Significance and Use5.1 The infrared energy that 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 reflecte
9、d temperatureerror source, the Reflector Method and the Direct Method.5.2 These test methods can be 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.1These test methods are u
10、nder the jurisdiction of ASTM Committee E07 onNondestructive Testing and are the direct responsibility of Subcommittee E07.10 onEmerging NDT Methods.Current edition approved April 10, 1997. Published June 1997.2Annual Book of ASTM Standards, Vol 03.03.1Copyright ASTM International, 100 Barr Harbor D
11、rive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Interferences6.1 Reflector Method:6.1.1 This test method uses an infrared reflector with anassumed reflectance of 1.00, which is an ideal property. Errorscan be minimized by using a reflector having a reflectance asclose as possib
12、le 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 specimen willreduce errors.6.2 Direct Method:6.2.1 The Direct Method usually does not account for theheat from the
13、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 pointsource, such as the sun or a lamp, are difficult to measureaccurately. These error sources can often be avoid
14、ed by movingthe infrared imaging radiometers position and angle relative tothe specimen.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 va
15、lue.6.5 The significance of the error contributed by reflectedtemperature can be estimated 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 thereflecti
16、on.7. Apparatus7.1 Calibrated Infrared Imaging Radiometer, with a built-incomputer with 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
17、 infrared reflector made from a piece of metal whosereflectance is as close as possible 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 t
18、othose of the specimen.8. Procedure8.1 Reflector Method:8.1.1 Set the infrared imaging 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
19、at the specimenand focus on the portion of the specimen where the reflectedtemperature 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 potentiallydangerou
20、s targets.8.1.5 Without moving the imager and using an appropriatemeasurement function (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 wh
21、en viewedfrom the position indicated in 8.1.2.8.1.6 Repeat 8.1.1-8.1.5 a minimum of three 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
22、on the tripod orsupport device at the desired location and distance from thespecimen.8.2.3 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 v
23、iewing the specimen with theinfrared imaging radiometer from this location (see Fig. 2).8.2.5 Remove the infrared imaging radiometer from thetripod and position it so that it is pointing away from theFIG. 1 Reflector MethodFIG. 2 Estimating the Angle of Reflection and IncidenceE 1862 97 (2002)e12spe
24、cimen 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 and record the apparent temperature reported by theradiometers computer. This is the reflected temperature of thisspec
25、imen 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 angle of incidence and average the reported temperatures.This average is the reflected temperature of the specimen w
26、henviewing 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.8.3 Compensate for the reflected temperature by enteringthe average reflected temperature in the reflected temperature
27、input of the radiometers computer, commonly referred to as“TAM,” “Ambient Temperature,” “Amb Temp” or “ReflectedBackground.”9. Precision and Bias9.1 PrecisionAn interlaboratory test program is not prac-tical here because of the nature of the specimens. However, ameasure of the precision of the test
28、methods can be inferredfrom the results of the replicate tests specified in 8.1.6 and8.2.7.9.2 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; infra
29、red examination; infrared re-flector; infrared testing; infrared thermography; nondestructivetesting; radiometry; reflected temperature; temperature com-pensation; temperature measurementASTM International takes no position respecting the validity of any patent rights asserted in connection with any
30、 item mentionedin this standard. Users of this standard 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
31、committee and must be reviewed every five years andif 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
32、 a meeting of theresponsible technical committee, which 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 D
33、rive, PO Box C700, West Conshohocken, PA 19428-2959,United 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).FIG. 3 Direct MethodE 1862 97 (2002)e13
