ASTM D542-22

Standard Test Method for Index of Refraction of Transparent Organic Plastics

SIGNIFICANCE AND USE
4.1 This test method measures a fundamental property of matter which is useful for the control of purity and composition for simple identification purposes, and for optical parts design. This test method is capable of readability to four figures to the right of the decimal point.
SCOPE
1.1 This test method covers a procedure for measuring the index of refraction of transparent organic plastic materials.  
1.2 A refractometer method is presented. This procedure will satisfactorily cover the range of refractive indices found for such materials. Refractive index measurements require optically homogeneous specimens of uniform refractive index.
Note 1: This test method and ISO 489 are technically equivalent.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Published
• Publication Date: 31-Aug-2022
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.40 - Optical Properties

Standards Content (Sample)

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.
Designation: D542 − 22
Standard Test Method for
1
Index of Refraction of Transparent Organic Plastics
This standard is issued under the fixed designation D542; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 2.2 ISO Standard:
ISO 489 Determination of the Refractive Index of Transpar-
1.1 This test method covers a procedure for measuring the
3
ent Plastics—Part A
index of refraction of transparent organic plastic materials.
1.2 A refractometer method is presented. This procedure 3. Terminology
will satisfactorily cover the range of refractive indices found
3.1 Definitions:
for such materials. Refractive index measurements require
3.1.1 Terms used in this standard are defined in accordance
optically homogeneous specimens of uniform refractive index.
with Terminology standards D883 and E284, unless otherwise
specified. For terms relating to precision and bias and associ-
NOTE 1—This test method and ISO 489 are technically equivalent.
ated issues, the terms used in this standard are defined in
1.3 This standard does not purport to address all of the
accordance with Terminology E456.
safety concerns, if any, associated with its use. It is the
3.1.2 dispersion—variation of refractive index with wave
responsibility of the user of this standard to establish appro-
length of light. C162, C14
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.1.3 index of refraction, n—thenumericalexpressionofthe
1.4 This international standard was developed in accor- ratio of the velocity of light in a vacuum to the velocity of light
dance with internationally recognized principles on standard- in a substance at a specified wavelength. E284, E12
ization established in the Decision on Principles for the
4. Significance and Use
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4.1 This test method measures a fundamental property of
Barriers to Trade (TBT) Committee.
matterwhichisusefulforthecontrolofpurityandcomposition
for simple identification purposes, and for optical parts design.
2. Referenced Documents
This test method is capable of readability to four figures to the
2
right of the decimal point.
2.1 ASTM Standards:
C162 Terminology of Glass and Glass Products
5. Apparatus
D618 Practice for Conditioning Plastics for Testing
5.1 The apparatus for this test method shall consist of an
D883 Terminology Relating to Plastics
Abbe’ refractometer (Note 2), a suitable source of white light,
E284 Terminology of Appearance
and a small quantity of a suitable contacting liquid (Note 2 and
E456 Terminology Relating to Quality and Statistics
Note 3).
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
NOTE 2—Other suitable refractometers can be used with appropriate
modification to this procedure as described in Section 7.
NOTE3—Asatisfactorycontactingliquidisonewhichwillnotsoftenor
1
otherwiseattackthesurfaceoftheplasticwithinaperiodof2hofcontact.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
The index of refraction of the liquid must be higher, but not less than one
and is the direct responsibility of Subcommittee D20.40 on Optical Properties.
unit in the second decimal place, than the index of the plastic being
Current edition approved Sept. 1, 2022. Published September 2022. Originally
measured; for example, n of the sample = 1.500, n of the contacting
approved in 1939. Last previous edition approved in 2014 as D542 - 14. DOI:
d d
10.1520/D0542-22. liquid ≥1.510.
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
3
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
1

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D542 − 22
6. Sampling the index arm of the refractometer until the field seen through
the eyepiece is one-half
...

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: D542 − 14 D542 − 22
Standard Test Method for
1
Index of Refraction of Transparent Organic Plastics
This standard is issued under the fixed designation D542; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers a procedure for measuring the index of refraction of transparent organic plastic materials.
1.2 A refractometer method is presented. This procedure will satisfactorily cover the range of refractive indices found for such
materials. Refractive index measurements require optically homogeneous specimens of uniform refractive index.
NOTE 1—This test method and ISO 489 are technically equivalent.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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.
2. Referenced Documents
2
2.1 ASTM Standards:
C162 Terminology of Glass and Glass Products
D618 Practice for Conditioning Plastics for Testing
D883 Terminology Relating to Plastics
E284 Terminology of Appearance
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 ISO Standard:
3
ISO 489 Determination of the Refractive Index of Transparent Plastics—Part A
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms Terms used in this test method, see Terminologies standard are defined in accordance with
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.40 on Optical Properties.
Current edition approved March 1, 2014Sept. 1, 2022. Published March 2014September 2022. Originally approved in 1939. Last previous edition approved in 20132014
as D542 - 13.D542 - 14. DOI: 10.1520/D0542-14.10.1520/D0542-22.
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.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D542 − 22
Terminology standards D883 and E284, unless otherwise specified. For terms relating to precision and bias and associated issues,
the terms used in this standard are defined in accordance with Terminology E456.
3.1.2 dispersion—variation of refractive index with wave length of light. C162, C14
3.1.3 index of refraction, n—the numerical expression of the ratio of the velocity of light in a vacuum to the velocity of light in
a substance at a specified wavelength. E284, E12
4. Significance and Use
4.1 This test method measures a fundamental property of matter which is useful for the control of purity and composition for
simple identification purposes, and for optical parts design. This test method is capable of readability to four figures to the right
of the decimal point.
5. Apparatus
5.1 The apparatus for this test method shall consist of an Abbe’ refractometer (Note 2), a suitable source of white light, and a small
quantity of a suitable contacting liquid (Note 2 and Note 3).
NOTE 2—Other suitable refractometers can be used with appropriate modification to this procedure as described in Section 7.
NOTE 3—A satisfactory contacting liquid is one which will not soften or otherwise attack the surface of the plastic within a period of 2 h of contact. The
index of refraction of the liquid must be hig
...