ASTM C148-12

Standard Test Methods for Polariscopic Examination of Glass Containers

SIGNIFICANCE AND USE
These two test methods are provided for evaluating the quality of annealing. These test methods can be used in the quality control of glass containers or other products made of similar glass compositions, where the degree of annealing must be verified to ensure quality products. These test methods apply to glass containers manufactured from commercial soda-lime-silica glass compositions.
SCOPE
1.1 These test methods describe the determination of relative optical retardation associated with the state of anneal of glass containers. Two alternative test methods are covered as follows:
  Sections  Test Method AComparison with Reference
Standards Using a Polariscope6 to 9 Test Method BDetermination with Polarimeter10 to 12
1.2 Test Method A is useful in determining retardations less than 150 nm, while Test Method B is useful in determining retardations less than 565 nm.
Note 1—The apparent temper number as determined by these test methods depends primarily on (1) the magnitude and distribution of the residual stress in the glass, (2) the thickness of the glass (optical path length at the point of grading), and ( 3) the composition of the glass. For all usual soda-lime silica bottle glass compositions, the effect of the composition is negligible. In an examination of the bottom of a container, the thickness of glass may be taken into account by use of the following formula, which defines a real temper number, TR, in terms of the apparent temper number, TA, and the bottom thickness, t:
TR = TA  (0.160/t)
where t is in inches, or
TR = TA  (4.06/t)
where t is in millimetres.
This thickness should be measured at the location of the maximum apparent retardation. Interpretation of either real or apparent temper number requires practical experience with the particular ware being evaluated.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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: 31-Mar-2012
• ICS: 55.100 - Bottles. Pots. Jars
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.07 - Glass Containers

Relations

• Replaces: ASTM C148-00(2011) - Standard Test Methods for Polariscopic Examination of Glass Containers
• Effective Date: 01-Apr-2012
• Replaced By: ASTM C148-14 - Standard Test Methods for Polariscopic Examination of Glass Containers
• Effective Date: 01-May-2014
• Referred By: ASTM E890-94(2021) - Standard Specification for Disposable Glass Culture Tubes
• Effective Date: 01-Apr-2012
• Referred By: ASTM C158-02(2017) - Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture)
• Effective Date: 01-Apr-2012
• Referred By: ASTM F2179-20 - Standard Specification for Annealed Soda-Lime-Silicate Glass Containers That Are Produced for Use as Candle Containers
• Effective Date: 01-Apr-2012
• Referred By: ASTM C1426-14(2020) - Standard Practices for Verification and Calibration of Polarimeters
• Effective Date: 01-Apr-2012
• Referred By: ASTM C162-05(2015) - Standard Terminology of<brk type="line"/> Glass and Glass Products
• Effective Date: 01-Apr-2012

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: C148 − 12
StandardTest Methods for
1
Polariscopic Examination of Glass Containers
This standard is issued under the fixed designation C148; 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 Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 These test methods describe the determination of rela- 2.1 ASTM Standards:
tive optical retardation associated with the state of anneal of C162 Terminology of Glass and Glass Products
glass containers. Two alternative test methods are covered as C224 Practice for Sampling Glass Containers
follows: C1426 Practices for Verification and Calibration of Polarim-
eters
Sections
Test Method A—Comparison with Reference 6 to 9
3. Terminology
Standards Using a Polariscope
Test Method B—Determination with Polarimeter 10 to 12 3.1 Definitions— For definitions of terms used in these test
methods see Terminology C162.
1.2 Test MethodAis useful in determining retardations less
than 150 nm, while Test Method B is useful in determining
4. Significance and Use
retardations less than 565 nm.
4.1 These two test methods are provided for evaluating the
NOTE 1—The apparent temper number as determined by these test
quality of annealing. These test methods can be used in the
methods depends primarily on (1) the magnitude and distribution of the
quality control of glass containers or other products made of
residual stress in the glass, (2) the thickness of the glass (optical path
length at the point of grading), and (3) the composition of the glass. For
similarglasscompositions,wherethedegreeofannealingmust
all usual soda-lime silica bottle glass compositions, the effect of the
be verified to ensure quality products. These test methods
composition is negligible. In an examination of the bottom of a container,
apply to glass containers manufactured from commercial
the thickness of glass may be taken into account by use of the following
soda-lime-silica glass compositions.
formula, which defines a real temper number, T , in terms of the apparent
R
temper number, T , and the bottom thickness, t:
A
T = T (0.160/t) 5. Sampling
R A
where t is in inches, or
5.1 Methods of sampling a minimum lot from a group of
T = T (4.06/t)
R A
containers of a given type are given in Practice C224 for the
where t is in millimetres.
This thickness should be measured at the location of the maximum
various situations to which that method may apply.
apparent retardation. Interpretation of either real or apparent temper
number requires practical experience with the particular ware being
TEST METHOD A—COMPARISON WITH
evaluated.
REFERENCE STANDARDS USING A POLARISCOPE
1.3 The values stated in SI units are to be regarded as the
6. Apparatus
standard. The values given in parentheses are for information
only.
6.1 Polariscope, conforming to the following requirements:
1.4 This standard does not purport to address all of the 6.1.1 The degree of polarization of the field at all points
shall not be less than 99 %.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 6.1.2 The field shall be a minimum of 51 mm (2 in.) in
diameter greater than the diameter of the container to be
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. measured. The distance between the polarizing and analyzing
elements shall be sufficient to allow the inside bottle bottom
surface to be viewed through the open container finish.
1
These test methods are under the jurisdiction of ASTM Committee C14 on
Glass and Glass Products and are the direct responsibility of Subcommittee C14.07
2
on Glass Containers. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2012. Published April 2012. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1939. Last previous edition approved in 2011 as C148 – 00 (2011). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C0148-12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C148 − 12
6.1.3 A sensitive tint plate, having a nominal optical retar- 8.3 Examination of the Container Sidewalls—Match the
dation of 565 nm, with a variation across the field of view of maximum retardation color observed in the container sidewall
less than 5 nm and with
...

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:C148–00 (Reapproved 2011) Designation:C148–12
Standard Test Methods for
1
Polariscopic Examination of Glass Containers
This standard is issued under the fixed designation C148; 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 Department of Defense.
1. Scope
1.1 These test methods describe the determination of relative optical retardation associated with the state of anneal of glass
containers. Two alternative test methods are covered as follows:
Sections
Test Method A—Comparison with Reference 6to9
Standards Using a Polariscope
Test Method B—Determination with Polarimeter 10 to 12
1.2 Test Method A is useful in determining retardations less than 150 nm, while Test Method B is useful in determining
retardations less than 565 nm.
NOTE 1—The apparent temper number as determined by these test methods depends primarily on (1) the magnitude and distribution of the residual
stress in the glass, (2) the thickness of the glass (optical path length at the point of grading), and ( 3) the composition of the glass. For all usual soda-lime
silica bottle glass compositions, the effect of the composition is negligible. In an examination of the bottom of a container, the thickness of glass may
betakenintoaccountbyuseofthefollowingformula,whichdefinesarealtempernumber, T ,intermsoftheapparenttempernumber, T ,andthebottom
R A
thickness, t:
T = T (0.160/t)
R A
where t is in inches, or
T = T (4.06/t)
R A
where t is in millimetres.
This thickness should be measured at the location of the maximum apparent retardation. Interpretation of either real or apparent temper number requires
practical experience with the particular ware being evaluated.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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:
C162 Terminology of Glass and Glass Products
C224 Practice for Sampling Glass Containers
C1426 Practices for Verification and Calibration of Polarimeters
3. Terminology
3.1 Definitions— For definitions of terms used in these test methods see Terminology C162.
4. Significance and Use
4.1 These two test methods are provided for evaluating the quality of annealing. These test methods can be used in the quality
control of glass containers or other products made of similar glass compositions, where the degree of annealing must be verified
to ensure quality products. These test methods apply to glass containers manufactured from commercial soda-lime-silica glass
compositions.
1
These test methods are under the jurisdiction ofASTM Committee C14 on Glass and Glass Products and are the direct responsibility of Subcommittee C14.07 on Glass
Containers.
Current edition approved April 1, 2011.2012. Published April 2011.2012. Originally approved in 1939. Last previous edition approved in 20062011 as C148 – 00
(2006).(2011). DOI: 10.1520/C0148-00R11.10.1520/C0148-12.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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 ----------------------
C148–12
5. Sampling
5.1 Methods of sampling a minimum lot from a group of containers of a given type are given in Practice C224 for the various
situations to which that method may apply.
TEST METHOD A—COMPARISON WITH REFERENCE STANDARDS USING A POLARISCOPE
6. Apparatus
6.1 Polariscope, conforming to the following requirements:
6.1.1 The degree of polarization of the field at all points shall not be less than 99 %.
6.1.2 The field shall be a minimum of 51 mm (2 in.) in diameter greater than the diameter of the container to be measured. The
distance between the polarizing and analyzing elements shall be sufficient to allow the inside bott
...