1、Designation: E1862 97 (Reapproved 2010)E1862 14Standard Test Methods Practice 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 ofori
2、ginal 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 These test methods cover procedures for measuring and compensa
3、ting for reflected temperature when measuring the surfacetemperature of a specimen with an infrared imaging radiometer.1.2 These test methods may involve use of equipment and materials in the presence of heated or electrically energizedequipment, or both.1.3 This standard does not purport to address
4、 all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1316 Terminology f
5、or Nondestructive Examinations3. Terminology3.1 Definitions:3.1.1 diffuse reflector, na surface that produces a diffuse image of a reflected source.3.1.2 infrared thermographer, nthe person using an infrared imaging radiometer.3.1.3 infrared reflector, na material with a reflectance as close as poss
6、ible to 1.00.3.1.4 reflected temperature, nthe temperature of the energy incident upon and reflected from the measurement surface of aspecimen.3.1.5 specular reflector, na surface that produces a direct image of a reflected source.3.2 See also Terminology E1316.4. Summary of Test Methods4.1 Two test
7、 methods are given for measuring the reflected temperature of a specimen, the Reflector Method and the DirectMethod.4.2 A test method is also given for compensating for the error produced by reflected temperature using the computer built intoan infrared imaging radiometer.5. Significance and Use5.1
8、The infrared energy that is reflected by a specimen can cause measurement errors for an infrared thermographer measuringits surface temperature. Two test methods are provided for measuring and compensating for this reflected temperature error source,the Reflector Method and the Direct Method.5.2 The
9、se test methods can be used in the field or laboratory using commonly available materials.1 These test methods are This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and are the direct responsibility of SubcommitteeE07.10 on Specialized NDT Methods.Current editio
10、n approved May 1, 2010Dec. 1, 2014. Published March 2011December 2014. Originally approved in 1997. Last previous edition approved in 20022010 asE1862 - 97(2002)(2010).1. DOI:10.1520/E1862-97R10. DOI:10.1520/E1862-14.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM
11、 Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made
12、to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyri
13、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 These test methods can be used with any infrared radiometers that have the required computer capabilities.6. Interferences6.1 Reflector Method:6.1.1 This test method uses an infrared refle
14、ctor with an assumed reflectance of 1.00, which is an ideal property. Errors can beminimized by using a reflector having a reflectance as close as possible to 1.00.6.1.2 Specimens vary in that they can be diffuse or spectral reflectors, or both. Use of an infrared reflector with reflectancepropertie
15、s as close as possible to those of the specimen will reduce errors.6.2 Direct Method:6.2.1 The Direct Method usually does not account for the heat from the infrared thermographers body as a source of reflectedtemperature. If this heat source creates a significant error, use the Reflector Method.6.3
16、Reflected temperature errors produced by a point source, such as the sun or a lamp, are difficult to measure accurately. Theseerror sources can often be avoided by moving the infrared imaging radiometers position and angle relative to the specimen.6.4 The measured reflected temperature of a specimen
17、 may be specific to the waveband of the infrared imaging radiometer used.Therefore, the infrared imaging radiometers waveband should be noted with the measured value.6.5 The significance of the error contributed by reflected temperature can be estimated by shielding the specimen from variousangles a
18、nd observing any changes in the thermal image.6.6 The error caused by reflected temperature can be reduced by shielding the specimen from the source of the reflection.7. Apparatus7.1 Calibrated Infrared Imaging Radiometer, with a built-in computer with the capability to measure temperatures with the
19、computers emissivity control set to 1.00.7.2 Tripod, or device to support the infrared imaging radiometer.7.3 Infrared ReflectorThe reflector method also requires an infrared reflector made from a piece of metal whose reflectanceis as close as possible to 1.00. Examples are a crumpled and re-flatten
20、ed piece of aluminum foil placed shiny side up on a pieceof cardboard, or a flat piece of metal with diffuse or spectral reflection characteristics, or both, similar to those of the specimen.8. Procedure8.1 Reflector Method:8.1.1 Set the infrared imaging radiometers emissivity control to 1.00.8.1.2
21、Place the infrared imaging radiometer on the tripod or support device at the desired location and distance from thespecimen.8.1.3 Point the infrared imaging radiometer at the specimen and focus on the portion of the specimen where the reflectedtemperature is to be measured.8.1.4 Place the infrared r
22、eflector in front of, and parallel to, the specimen (see Fig. 1). Maintain a safe working distance fromany heated, electrically energized or otherwise potentially dangerous targets.8.1.5 Without moving the imager and using an appropriate measurement function (such as spot temperature, cross hairs or
23、isotherms), measure and record the apparent surface temperature of the reflector reported by the radiometers computer. This is thereflected temperature of this specimen when viewed from the position indicated in 8.1.2.8.1.6 Repeat 8.1.1 8.1.5 a minimum of three times and average the temperatures to
24、yield an average reflected temperature.8.2 Direct Method:8.2.1 Set the infrared imaging radiometers emissivity control to 1.00.8.2.2 Place the infrared imaging radiometer on the tripod or support device at the desired location and distance from thespecimen.8.2.3 Point the infrared imaging radiometer
25、 at the specimen and focus on the portion where the reflected temperature is to bemeasured.FIG. 1 Reflector MethodE1862 1428.2.4 Estimate or measure the angle of reflection and the angle of incidence when viewing the specimen with the infraredimaging radiometer from this location (see Fig. 2).8.2.5
26、Remove the infrared imaging radiometer from the tripod and position it so that it is pointing away from the specimen andin the same direction as the angle of reflection (see Fig. 3, Line A). Using an appropriate measurement function (such as spottemperature, cross hairs or isotherms), measure and re
27、cord the apparent temperature reported by the radiometers computer. Thisis the reflected temperature of this specimen when viewed from the position indicated in 8.2.2.8.2.6 If the specimen surface is a diffuse reflector, point the radiometer at a variety of locations within 45 of both sides of thean
28、gle of incidence and average the reported temperatures. This average is the reflected temperature of the specimen when viewingthe specimen from the position indicated in 8.2.2.8.2.7 Repeat 8.2.1 8.2.6 a minimum of three times and average the temperatures to yield an average reflected temperature.8.3
29、 Compensate for the reflected temperature by entering the average reflected temperature in the reflected temperature inputof the radiometers computer, commonly referred to as “TAM,” “Ambient Temperature,” “Amb Temp” or “Reflected Background.”9. Precision and Bias9.1 PrecisionAn interlaboratory test
30、program is not practical here because of the nature of the specimens. However, a measureof the precision of the test methods can be inferred from the results of the replicate tests specified in 8.1.6 and 8.2.7.9.2 BiasThese test methods for measuring reflected temperature have no bias because the va
31、lues of reflected temperature aredefined only in terms of the test methods.FIG. 3 Direct MethodFIG. 2 Estimating the Angle of Reflection and IncidenceE1862 14310. Keywords10.1 imaging; infrared; infrared examination; infrared reflector; infrared testing; infrared thermography; nondestructive testing
32、radiometry; reflected temperature; temperature compensation; 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 determination of th
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37、ter, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ Scope*1.1 This practice covers procedures for measuring and compensating for reflected temperature when measuring the surfacetemperature of a specimen with an infrared imaging radiometer.21.2 These procedures may involve use of e
38、quipment and materials in the presence of heated or electrically energized equipment,or both.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health prac
39、tices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E1316 Terminology for Nondestructive Examinations3. Terminology3.1 Definitions:3.1.1 diffuse reflector, na surface that produces a diffuse image of a reflected source.3.1.2 infrared
40、 thermographer, nthe person using an infrared imaging radiometer.3.1.3 infrared reflector, na material with a reflectance as close as possible to 1.00.3.1.4 reflected temperature, nthe temperature of the energy incident upon and reflected from the measurement surface of aspecimen.3.1.5 specular refl
41、ector, na surface that produces a direct image of a reflected source.3.2 See also Terminology E1316.4. Summary of Procedure4.1 Two procedures are given for measuring the reflected temperature of a specimen, the Reflector Method and the DirectMethod.4.2 A procedure is also given for compensating for
42、the error produced by reflected temperature using the computer built intoan infrared imaging radiometer.5. Significance and Use5.1 The infrared energy that is reflected by a specimen can cause measurement errors for an infrared thermographer measuringits surface temperature. Two procedures are provi
43、ded for measuring and compensating for this reflected temperature error source,the Reflector Method and the Direct Method.5.2 These procedures can be used in the field or laboratory using commonly available materials.5.3 These procedures can be used with any infrared radiometers that have the requir
44、ed computer capabilities.2 This practice was originally adapted in 1997, by agreement, from the Guideline for Measuring and Compensating for Reflected Temperature, Emittance andTransmittance developed by Infraspection Institute, 425 Ellis Street, Burlington, NJ 08016.E1862 1445.4 Due to the nature o
45、f the specimens, the repeatability and reproducibility are subjective. However, a measure of the precisionof the procedures can be inferred from the results of the replicate procedures specified in 8.1.6 and 8.2.7.6. Interferences6.1 Reflector Method:6.1.1 This procedure uses an infrared reflector w
46、ith an assumed reflectance of 1.00, which is an ideal property. Errors can beminimized by using a reflector having a reflectance as close as possible to 1.00.6.1.2 Specimens vary in that they can be diffuse or spectral reflectors, or both. Use of an infrared reflector with reflectanceproperties as c
47、lose as possible to those of the specimen will reduce errors.6.2 Direct Method:6.2.1 The Direct Method usually does not account for the heat from the infrared thermographers body as a source of reflectedtemperature. If this heat source creates a significant error, use the Reflector Method.6.3 Reflec
48、ted temperature errors produced by a point source, such as the sun or a lamp, are difficult to measure accurately. Theseerror sources can often be avoided by moving the infrared imaging radiometers position and angle relative to the specimen.6.4 The measured reflected temperature of a specimen may b
49、e specific to the waveband of the infrared imaging radiometer used.Therefore, the infrared imaging radiometers waveband should be noted with the measured value.6.5 The significance of the error contributed by reflected temperature can be estimated by shielding the specimen from variousangles and observing any changes in the thermal image.6.6 The error caused by reflected temperature can be reduced by shielding the specimen from the source of the reflection.7. Apparatus7.1 Calibrated Infrared Imaging Radiometer, with a built-in
