ASTM E1862-97(2010)
(Test Method)Standard Test Methods for Measuring and Compensating for Reflected Temperature Using Infrared Imaging Radiometers
Standard Test Methods for Measuring and Compensating for Reflected Temperature Using Infrared Imaging Radiometers
SIGNIFICANCE AND USE
The infrared energy that is reflected by a specimen can cause measurement errors for an infrared thermographer measuring its surface temperature. Two test methods are provided for measuring and compensating for this reflected temperature error source, the Reflector Method and the Direct Method.
These test methods can be used in the field or laboratory using commonly available materials.
These test methods can be used with any infrared radiometers that have the required computer capabilities.
SCOPE
1.1 These test methods cover procedures for measuring and compensating for reflected temperature when measuring the surface temperature 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 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 responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation:E1862 −97(Reapproved 2010)
Standard Test Methods for
Measuring and Compensating for Reflected Temperature
Using Infrared Imaging Radiometers
This standard is issued under the fixed designation E1862; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 See also Terminology E1316.
1.1 These test methods cover procedures for measuring and
4. Summary of Test Methods
compensating for reflected temperature when measuring the
4.1 Two test methods are given for measuring the reflected
surface temperature of a specimen with an infrared imaging
temperature of a specimen, the Reflector Method and the
radiometer.
Direct Method.
1.2 These test methods may involve use of equipment and
4.2 A test method is also given for compensating for the
materials in the presence of heated or electrically energized
error produced by reflected temperature using the computer
equipment, or both.
built into an infrared imaging radiometer.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Significance and Use
responsibility of the user of this standard to establish appro-
5.1 The infrared energy that is reflected by a specimen can
priate safety and health practices and determine the applica-
cause measurement errors for an infrared thermographer mea-
bility of regulatory limitations prior to use.
suring its surface temperature. Two test methods are provided
for measuring and compensating for this reflected temperature
2. Referenced Documents
error source, the Reflector Method and the Direct Method.
2.1 ASTM Standards:
5.2 These test methods can be used in the field or laboratory
E1316 Terminology for Nondestructive Examinations
using commonly available materials.
3. Terminology
5.3 These test methods can be used with any infrared
radiometers that have the required computer capabilities.
3.1 Definitions:
3.1.1 diffuse reflector, n—a surface that produces a diffuse
6. Interferences
image of a reflected source.
6.1 Reflector Method:
3.1.2 infrared thermographer, n—the person using an infra-
6.1.1 This test method uses an infrared reflector with an
red imaging radiometer.
assumed reflectance of 1.00, which is an ideal property. Errors
3.1.3 infrared reflector, n—a material with a reflectance as
can be minimized by using a reflector having a reflectance as
close as possible to 1.00.
close as possible to 1.00.
3.1.4 reflected temperature, n—the temperature of the en-
6.1.2 Specimens vary in that they can be diffuse or spectral
ergy incident upon and reflected from the measurement surface
reflectors, or both. Use of an infrared reflector with reflectance
of a specimen.
properties as close as possible to those of the specimen will
reduce errors.
3.1.5 specular reflector, n—a surface that produces a direct
image of a reflected source.
6.2 Direct Method:
6.2.1 The Direct Method usually does not account for the
heat from the infrared thermographer’s body as a source of
These test methods are under the jurisdiction of ASTM Committee E07 on
reflected temperature. If this heat source creates a significant
Nondestructive Testing and are the direct responsibility of Subcommittee E07.10 on
Specialized NDT Methods.
error, use the Reflector Method.
Current edition approved May 1, 2010. Published March 2011. Originally
ϵ1
6.3 Reflected temperature errors produced by a point
approved in 1997. Last previous edition approved in 2002 as E1862 - 97(2002) .
DOI:10.1520/E1862-97R10.
source, such as the sun or a lamp, are difficult to measure
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
accurately.Theseerrorsourcescanoftenbeavoidedbymoving
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
the infrared imaging radiometer’s position and angle relative to
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the specimen.
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E1862−97 (2010)
FIG. 1 Reflector Method
6.4 The measured reflected temperature of a specimen may
be specific to the waveband of the infrared imaging radiometer
used. Therefore, the infrared imaging radiometer’s 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
various angles and observing any changes in the thermal
image.
6.6 The error caused by reflected temperature can be re- FIG. 2 Estimating the Angle of Reflection and Incidence
duced by shielding the specimen from the source of the
reflection.
8.1.6 Repeat 8.1.1-8.1.5 a minimum of three times and
average the temperatures to yield an average reflected tempera-
7. Apparatus
ture.
7.1 Calibrated Infrared Imaging Radiometer, with a built-in
8.2 Direct Method:
computer with the capability to measure temperatur
...
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