ASTM G138-03

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:G138–03
Standard Test Method for
Calibration of a Spectroradiometer Using a Standard Source
1
of Irradiance
This standard is issued under the fixed designation G138; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Astandardized means of performing and reporting calibration of the spectroradiometer for spectral
irradiance measurements is desirable.
This test method presents specific technical requirements for a laboratory performing calibration of
a spectroradiometer for spectral irradiance measurements. A detailed procedure for performing the
calibration and reporting the results is outlined.
This test method for calibration is applicable to spectroradiometric systems consisting of at least a
monochromator, input optics, and an optical radiation detector, and applies to spectroradiometric
calibrations performed with a standard of spectral irradiance with known irradiance values traceable
to the National Institute of Standards and Technology (NIST) or other national standards laboratory.
The standard must also have known uncertainties and measurement geometry associated with its
irradiance values.
1. Scope problems and have limited dynamic range. Diode array spec-
troradiometers are not recommended for use in the ultraviolet
1.1 This test method covers the calibration of spectroradi-
range unless these specific problems are addressed.
ometers for the measurement of spectral irradiance using a
1.4 The calibration described in this method employs the
standard of spectral irradiance that is traceable to NIST.
use of a standard of spectral irradiance. The standard of
NOTE 1—Although NIST is referenced throughout this standard, it
spectral irradiance must have known spectral irradiance values
should be assumed that other internationally recognized standards labo-
at given wavelengths for a specific input current and clearly
ratories may be substituted.
defined measurement geometry. Uncertainties must also be
1.2 This method is not limited by the input optics of the
known for the spectral irradiance values. The values assigned
spectroradiometric system. However, choice of input optics
to this standard must be traceable to NIST. These standards
affects the overall uncertainty of the calibration.
may be obtained from a number of national standards labora-
1.3 This method is not limited by the type of monochroma-
tories and commercial laboratories. The spectral irradiance
tor or optical detector used in the spectroradiometer system.
standardsconsistmainlyoftungstenhalogenlampswithcoiled
Parts of the method may not apply to determine which parts
filaments enclosed in a quartz envelope, though other types of
apply to the specific spectroradiometer being used. It is
lamps are used. Standards can be obtained with calibration
important that the choice of monochromator and detector be
valuescoveringallorpartofthewavelengthrangefrom200to
appropriate for the wavelength range of interest for the
4500 nm.
calibration. Though the method generally applies to photo-
1.5 This standard does not purport to address all of the
diode array detector based systems, the user should note that
safety concerns, if any, associated with its use. It is the
these types of spectroradiometers often suffer from stray light
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
2
bility of regulatory limitations prior to use.
1
This test method is under the jurisdiction of ASTM Committee G03 on
DurabilityofNonmetallicMaterialsandisthedirectresponsibilityofSubcommittee
G03.09 on Ultraviolet Radiation Measurement Standards.
2
Current edition approved June 10, 2003. Published July 2003. Originally Available from Secretary, U.S. National Committee, CIE, National Institute of
published as G138–96. Last previous edition G138–96. Standards and Technology, Gaithersburg, MD 20899.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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G138–03
2. Referenced Documents 3.2.3 primary standard of spectral irradiance, n—a broad
spectrum light source with known spectral irradiance values at
2.1 ASTM Standards:
3 various wavelengths which are traceable to NIST.
E772 Terminology Relating to Solar Energy Conversion
3.2.4 responsivity, n—symbol R = dS/df, S is signal from
E1341 Practice for Obtaining Spectroradiometric Data
4 spectroradiometer detector, f is radiant flux at the detector.
from Radiant Sources
3.2.5 secondary standard of spectral irradiance,
...