ASTM C148-17(2022)
Standard Test Methods for Polariscopic Examination of Glass Containers

Standard No.

ASTM C148-17(2022)

Release Date

2022

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM C148-17(2022)

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 Standards Using a Polariscope 6 – 9 Test Method B—Determination with Polarimeter 10 – 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 5 TA~0.160 ⁄ t!, where t is in inches, or TR 5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 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 C148-17(2022) Referenced Document

• ASTM C1426 Standard Practices for Verification and Calibration of Polarimeters
• ASTM C162 Standard Terminology of Glass and Glass Products
• ASTM C224 Standard Practice for Sampling Glass Containers

ASTM C148-17(2022) history

• 2022 ASTM C148-17(2022) Standard Test Methods for Polariscopic Examination of Glass Containers
• 2017 ASTM C148-17 Standard Test Methods for Polariscopic Examination of Glass Containers
• 2014 ASTM C148-14 Standard Test Methods for Polariscopic Examination of Glass Containers
• 2012 ASTM C148-12 Standard Test Methods for Polariscopic Examination of Glass Containers
• 2000 ASTM C148-00(2011) Standard Test Methods for Polariscopic Examination of Glass Containers
• 2000 ASTM C148-00(2006) Standard Test Methods for Polariscopic Examination of Glass Containers
• 2000 ASTM C148-00 Standard Test Methods for Polariscopic Examination of Glass Containers