ASTM G138-12(2020)e1
Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance

Standard No.

ASTM G138-12(2020)e1

Release Date

2020

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM G138-12(2020)e1

Scope

1.1 This test method covers the calibration of spectroradiometers for the measurement of spectral irradiance using a standard of spectral irradiance that is traceable to a national metrological laboratory that has participated in intercomparisons of standards of spectral irradiance. 1.2 This method is not limited by the input optics of the spectroradiometric system. However, choice of input optics affects the overall uncertainty of the calibration. 1.3 This method is not limited by the type of monochromator or optical detector used in the spectroradiometer system. Parts of the method may not apply to determine which parts apply to the specific spectroradiometer being used. It is important that the choice of monochromator and detector be appropriate for the wavelength range of interest for the calibration. Though the method generally applies to photodiode array detector based systems, the user should note that these types of spectroradiometers often suffer from stray light problems and have limited dynamic range. Diode array spectroradiometers are not recommended for use in the ultraviolet range unless these specific problems are addressed. 1.4 The calibration described in this method employs the use of a standard of spectral irradiance. The standard of spectral irradiance must have known spectral irradiance values at given wavelengths for a specific input current and clearly defined measurement geometry. Uncertainties must also be known for the spectral irradiance values. The values assigned to this standard must be traceable to a national metrological laboratory that has participated in intercomparisons of standards of spectral irradiance. These standards may be obtained from a number of national standards laboratories and commercial laboratories. The spectral irradiance standards consist mainly of tungsten halogen lamps with coiled filaments enclosed in a quartz envelope, though other types of lamps are used. Standards can be obtained with calibration values covering all or part of the wavelength range from 200 to 4500 nm. 1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.2 1 This test method is under the jurisdiction of ASTM Committee G03 on Weathering and Durability and is the direct responsibility of Subcommittee G03.09 on Radiometry. Current edition approved June 1, 2020. Published July 2020. Originally approved in 1996. Last previous edition approved in 2012 as G138 – 12. DOI: 10.1520/ G0138-12R20E01. 2 Available from the CIE, (International Commission on Illumination), http:// www.techstreet.com/ciegate.tmpl CIE Central Bureau, Kegelgasse 27, A-1030 Vienna, Austria. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM G138-12(2020)e1 Referenced Document

• ASTM E1341 Standard Practice for Obtaining Spectroradiometric Data from Radiant Sources for Colorimetry
• ASTM E772 Standard Terminology Relating to Solar Energy Conversion

ASTM G138-12(2020)e1 history

• 2020 ASTM G138-12(2020)e1 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance
• 2012 ASTM G138-12 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance
• 2006 ASTM G138-06 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance
• 2003 ASTM G138-03 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance
• 1996 ASTM G138-96 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance