ASTM E973-16

Standard Test Method for Determination of the Spectral Mismatch Parameter Between a Photovoltaic Device and a Photovoltaic Reference Cell

SIGNIFICANCE AND USE
5.1 The calculated error in the photovoltaic device current determined from the spectral mismatch parameter can be used to determine if a measurement will be within specified limits before the actual measurement is performed.  
5.2 The spectral mismatch parameter also provides a means of correcting the error in the measured device current due to spectral mismatch.  
5.2.1 The spectral mismatch parameter is formulated as the fractional error in the short-circuit current due to spectral and temperature differences.  
5.2.2 Error due to spectral mismatch is corrected by multiplying a reference cell’s measured short-circuit current by M , a technique used in Test Methods E948 and E1036.  
5.3 Because all spectral quantities appear in both the numerator and the denominator in the calculation of the spectral mismatch parameter (see 8.1), multiplicative calibration errors cancel, and therefore only relative quantities are needed (although absolute spectral quantities may be used if available).  
5.4 Temperature-dependent spectral mismatch is a more accurate method to correct photovoltaic current measurements compared with fixed-value temperature coefficients.3
SCOPE
1.1 This test method provides a procedure for the determination of a spectral mismatch parameter used in performance testing of photovoltaic devices.  
1.2 The spectral mismatch parameter is a measure of the error introduced in the testing of a photovoltaic device that is caused by the photovoltaic device under test and the photovoltaic reference cell having non-identical quantum efficiencies, as well as mismatch between the test light source and the reference spectral irradiance distribution to which the photovoltaic reference cell was calibrated.  
1.2.1 Examples of reference spectral irradiance distributions are Tables E490 or G173.  
1.3 The spectral mismatch parameter can be used to correct photovoltaic performance data for spectral mismatch error.  
1.4 Temperature-dependent quantum efficiencies are used to quantify the effects of temperature differences between test conditions and reporting conditions.  
1.5 This test method is intended for use with linear photovoltaic devices in which short-circuit is directly proportional to incident irradiance.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 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.

General Information

• Status: Historical
• Publication Date: 30-Jun-2016
• ICS: 27.160 - Solar energy engineering
• Technical Committee: E44 - Solar, Geothermal and Other Alternative Energy Sources
• Drafting Committee: E44.09 - Photovoltaic Electric Power Conversion

Relations

• Replaces: ASTM E973-15 - Standard Test Method for Determination of the Spectral Mismatch Parameter Between a Photovoltaic Device and a Photovoltaic Reference Cell
• Effective Date: 01-Jul-2016
• Replaced By: ASTM E973-16(2020) - Standard Test Method for Determination of the Spectral Mismatch Parameter Between a Photovoltaic Device and a Photovoltaic Reference Cell
• Effective Date: 01-Jun-2020
• Referred By: ASTM E948-16(2020) - Standard Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated Sunlight
• Effective Date: 01-Jul-2016
• Referred By: ASTM E1125-16(2020) - Standard Test Method for Calibration of Primary Non-Concentrator Terrestrial Photovoltaic Reference Cells Using a Tabular Spectrum
• Effective Date: 01-Jul-2016
• Referred By: ASTM G113-22 - Standard Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
• Effective Date: 01-Jul-2016
• Referred By: ASTM E927-19 - Standard Classification for Solar Simulators for Electrical Performance Testing of Photovoltaic Devices
• Effective Date: 01-Jul-2016
• Referred By: ASTM E2236-10(2019) - Standard Test Methods for Measurement of Electrical Performance and Spectral Response of Nonconcentrator Multijunction Photovoltaic Cells and Modules
• Effective Date: 01-Jul-2016
• Referred By: ASTM G214-23 - Standard Test Method for Integration of Digital Spectral Data for Weathering and Durability Applications
• Effective Date: 01-Jul-2016
• Referred By: ASTM E1036-15(2019) - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Jul-2016
• Referred By: ASTM E2848-13(2023) - Standard Test Method for Reporting Photovoltaic Non-Concentrator System Performance
• Effective Date: 01-Jul-2016
• Referred By: ASTM E1362-15(2019) - Standard Test Methods for Calibration of Non-Concentrator Photovoltaic Non-Primary Reference Cells
• Effective Date: 01-Jul-2016
• Referred By: ASTM E1021-15(2019) - Standard Test Method for Spectral Responsivity Measurements of Photovoltaic Devices
• Effective Date: 01-Jul-2016
• Referred By: ASTM G130-12(2020) - Standard Test Method for Calibration of Narrow- and Broad-Band Ultraviolet Radiometers Using a Spectroradiometer
• Effective Date: 01-Jul-2016

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E973 − 16 An American National Standard
Standard Test Method for
Determination of the Spectral Mismatch Parameter Between
1
a Photovoltaic Device and a Photovoltaic Reference Cell
This standard is issued under the fixed designation E973; 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 mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method provides a procedure for the determi-
nation of a spectral mismatch parameter used in performance
2. Referenced Documents
testing of photovoltaic devices.
2
2.1 ASTM Standards:
1.2 The spectral mismatch parameter is a measure of the
E490 Standard Solar Constant and Zero Air Mass Solar
error introduced in the testing of a photovoltaic device that is
Spectral Irradiance Tables
caused by the photovoltaic device under test and the photovol-
E772 Terminology of Solar Energy Conversion
taic reference cell having non-identical quantum efficiencies,
E948 Test Method for Electrical Performance of Photovol-
as well as mismatch between the test light source and the
taic Cells Using Reference Cells Under Simulated Sun-
reference spectral irradiance distribution to which the photo-
light
voltaic reference cell was calibrated.
E1021 TestMethodforSpectralResponsivityMeasurements
1.2.1 Examplesofreferencespectralirradiancedistributions
of Photovoltaic Devices
are Tables E490 or G173.
E1036 Test Methods for Electrical Performance of Noncon-
centrator Terrestrial Photovoltaic Modules and Arrays
1.3 The spectral mismatch parameter can be used to correct
Using Reference Cells
photovoltaic performance data for spectral mismatch error.
E1125 Test Method for Calibration of Primary Non-
1.4 Temperature-dependent quantum efficiencies are used to
Concentrator Terrestrial Photovoltaic Reference Cells Us-
quantify the effects of temperature differences between test
ing a Tabular Spectrum
conditions and reporting conditions.
E1362 Test Methods for Calibration of Non-Concentrator
1.5 This test method is intended for use with linear photo-
Photovoltaic Non-Primary Reference Cells
voltaic devices in which short-circuit is directly proportional to G138 Test Method for Calibration of a Spectroradiometer
incident irradiance.
Using a Standard Source of Irradiance
G173 TablesforReferenceSolarSpectralIrradiances:Direct
1.6 The values stated in SI units are to be regarded as
Normal and Hemispherical on 37° Tilted Surface
standard. No other units of measurement are included in this
SI10 Standard for Use of the International System of Units
standard.
(SI): The Modern Metric System
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—Definitions of terms used in this test
priate safety, health, and environmental practices and deter-
method may be found in Terminology E772.
mine the applicability of regulatory limitations prior to use.
3.2 Definitions of Terms Specific to This Standard:
1.8 This international standard was developed in accor-
3.2.1 test light source, n—a source of illumination whose
dance with internationally recognized principles on standard-
spectral irradiance will be used for the spectral mismatch
ization established in the Decision on Principles for the
calculation. The light source may be natural sunlight or a solar
Development of International Standards, Guides and Recom-
simulator.
3.3 Symbols: The following symbols and units are used in
this test method:
1
This test method is under the jurisdiction of ASTM Committee E44 on Solar,
Geothermal and OtherAlternative Energy Sources and is the direct responsibility of
2
Subcommittee E44.09 on Photovoltaic Electric Power Conversion. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2016. Published August 2016. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1983. Last previous edition approved in 2015 as E973 –15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0973-16. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E973 − 16
3.3.1 λ—wavelength (µm or nm). be tested differ from one another; these quantum efficiencies
vary with temperature.
3.3.2 D—as a subscript, refers to the device to be tested.
4.3 Determination
...

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 to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: E973 − 15 E973 − 16
Standard Test Method for
Determination of the Spectral Mismatch Parameter Between
1
a Photovoltaic Device and a Photovoltaic Reference Cell
This standard is issued under the fixed designation E973; 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
1.1 This test method provides a procedure for the determination of a spectral mismatch parameter used in performance testing
of photovoltaic devices.
1.2 The spectral mismatch parameter is a measure of the error introduced in the testing of a photovoltaic device that is caused
by the photovoltaic device under test and the photovoltaic reference cell having non-identical quantum efficiencies, as well as
mismatch between the test light source and the reference spectral irradiance distribution to which the photovoltaic reference cell
was calibrated.
1.2.1 Examples of reference spectral irradiance distributions are Tables E490 or G173.
1.3 The spectral mismatch parameter can be used to correct photovoltaic performance data for spectral mismatch error.
1.4 Temperature-dependent quantum efficiencies are used to quantify the effects of temperature differences between test
conditions and reporting conditions.
1.5 This test method is intended for use with linear photovoltaic devices in which short-circuit is directly proportional to
incident irradiance.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E490 Standard Solar Constant and Zero Air Mass Solar Spectral Irradiance Tables
E772 Terminology of Solar Energy Conversion
E948 Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated Sunlight
E1021 Test Method for Spectral Responsivity Measurements of Photovoltaic Devices
E1036 Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using
Reference Cells
E1125 Test Method for Calibration of Primary Non-Concentrator Terrestrial Photovoltaic Reference Cells Using a Tabular
Spectrum
E1362 Test Methods for Calibration of Non-Concentrator Photovoltaic Non-Primary Reference Cells
G138 Test Method for Calibration of a Spectroradiometer Using a Standard Source of Irradiance
G173 Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37° Tilted Surface
SI10 Standard for Use of the International System of Units (SI): The Modern Metric System
3. Terminology
3.1 Definitions—Definitions of terms used in this test method may be found in Terminology E772.
3.2 Definitions of Terms Specific to This Standard:
1
This test method is under the jurisdiction of ASTM Committee E44 on Solar, Geothermal and Other Alternative Energy Sources and is the direct responsibility of
Subcommittee E44.09 on Photovoltaic Electric Power Conversion.
Current edition approved Dec. 1, 2015July 1, 2016. Published January 2016August 2016. Originally approved in 1983. Last previous edition approved in 2015 as
E973 –10(2015). –15. DOI: 10.1520/E0973-15.10.1520/E0973-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E973 − 16
3.2.1 test light source, n—a source of illumination whose spectral irradiance will be used for the spectral mismatch calculation.
The light source may be natural sunlight or a solar simulator.
3.3 Symbols: The following symbols and units are used in this test method:
3.3.1 λ—wavelength (μm or nm).
3.3.2 D—as a subscript, refers to the device to be tested.
3.3.3 R—as a subscript, refers to the reference cell.
3.3.4 S—as a subscript, refers to the test light source.
3.3.5 0—as a subscript, refer
...