ISO 21575:2018
(Main)Optics and photonics - Optical materials and components - The powder test method for the water resistance of optical glass
Optics and photonics - Optical materials and components - The powder test method for the water resistance of optical glass
This document specifies the general procedures of the powder test method for the water resistance of optical glass.
Optique et photonique — Matériaux et composants optiques — Méthode d'essai sur poudre pour déterminer la résistance à l'eau des verres optiques
General Information
- Status
- Published
- Publication Date
- 27-Jun-2018
- Technical Committee
- ISO/TC 172/SC 3 - Optical materials and components
- Drafting Committee
- ISO/TC 172/SC 3/WG 1 - Raw optical glass
- Current Stage
- 9092 - International Standard to be revised
- Start Date
- 21-Dec-2023
- Completion Date
- 13-Dec-2025
Relations
- Effective Date
- 23-Dec-2023
Overview
ISO 21575:2018 - Optics and photonics - The powder test method for the water resistance of optical glass - specifies the general procedures for evaluating the water resistance of optical glass using the powder test method. The standard defines specimen preparation, required apparatus, reagents, test procedure and classification by percentage weight loss after boiling in water. The powder method is an alternative to the surface method and is noted for simpler sample preparation because it does not require polished surfaces.
Key topics and technical requirements
Specimen preparation
- Grind glass and sieve to collect particle sizes between 425 µm and 600 µm.
- Wash/de-dust by repeated decantation with pure alcohol, then dry at 120–130 °C and store in a desiccator.
- Sample mass: use a powder mass equivalent to the glass specific gravity (grams) in the test basket and use ~3× specific gravity for initial decantation steps.
Reagents and water quality
- Water must meet ISO 3696 Grade 2 (analytical laboratory water).
- Alcohols allowed: ethanol, methanol, 2‑propanol (no water-containing alcohol).
Apparatus
- Test sieves per ISO 3310‑1.
- Platinum mesh basket for corrosion test: opening 230–260 µm, wire diameter ≈ 76 µm.
- Flask and condenser conforming to ISO 4797 / ISO 4799; nominal spherical flask capacity 100 ml.
- Heating water bath maintaining temperature > 98 °C (measured 20 mm ± 10 mm from flask bottom).
Test procedure
- Place powdered specimen in platinum basket, weigh, boil in 80 ml pure water for 60 minutes, rinse with alcohol, dry (120–130 °C), cool in desiccator and weigh.
- Repeat the full procedure twice; calculate percentage weight loss from initial mass and report mean of two measurements.
Classification
- Water resistance classes 1 to 6 based on percentage weight loss. (Class thresholds per Table 1 in ISO 21575:2018: e.g., Class 1 <0.05%, Class 2 <0.10%, Class 3 <0.25%, Class 4 <0.60%, Class 5 <1.10%, Class 6 ≥1.10%.)
Applications and users
- Intended for optical glass manufacturers, quality control and test laboratories, materials scientists, and photonics component producers.
- Practical uses:
- Material selection and specification for lenses, prisms, windows and optical components exposed to moisture or humid environments.
- Quality control, acceptance testing and comparative assessment of chemical durability among glass batches.
- R&D for new optical glass formulations where water resistance is a performance parameter.
Related standards
- ISO 3310‑1 (Test sieves)
- ISO 3696 (Water for analytical laboratory use)
- ISO 4797, ISO 4799 (Laboratory glassware - boiling flasks and condensers)
Keywords: ISO 21575:2018, powder test method, water resistance, optical glass, optics and photonics, optical materials, weight loss classification, platinum basket, test procedure.
ISO 21575:2018 - Optics and photonics -- Optical materials and components -- The powder test method for the water resistance of optical glass
REDLINE ISO 21575:2018 - Optics and photonics — Optical materials and components — The powder test method for the water resistance of optical glass Released:6/28/2018
Frequently Asked Questions
ISO 21575:2018 is a standard published by the International Organization for Standardization (ISO). Its full title is "Optics and photonics - Optical materials and components - The powder test method for the water resistance of optical glass". This standard covers: This document specifies the general procedures of the powder test method for the water resistance of optical glass.
This document specifies the general procedures of the powder test method for the water resistance of optical glass.
ISO 21575:2018 is classified under the following ICS (International Classification for Standards) categories: 37.020 - Optical equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 21575:2018 has the following relationships with other standards: It is inter standard links to ISO 21575. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ISO 21575:2018 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 21575
First edition
2018-06
Optics and photonics — Optical
materials and components — The
powder test method for the water
resistance of optical glass
Optique et photonique — Matériaux et composants optiques —
Méthode d'essai sur poudre pour déterminer la résistance à l'eau des
verres optiques
Reference number
©
ISO 2018
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles . 1
5 Reagents . 1
5.1 Water . 1
5.2 Alcohol. 1
6 Apparatus . 2
6.1 Sieve . 2
6.2 Basket for corrosion test . 2
6.3 Apparatus for corrosion test . 2
6.4 Heating bath . 3
7 Preparation of the specimen of the glass to be tested . 3
8 Procedure. 3
9 Classification and designation . 4
10 Test report . 4
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformit
...
ISO 21575:2018(E)
INTERNATIONAL STANDARD
ISO
Deleted: /FDIS
Deleted: :
First edition
2018-06 Deleted: (E)
Deleted: ISO/TC 172/SC 3/WG 1¶
Optics and photonics — Optical materials and components
— The powder test method for the water resistance of
optical glass
Optique et photonique — Matériaux et composants optiques — Méthode d'essai sur poudre pour Deleted: Élément introductif —
Élément central — Élément
déterminer la résistance à l'eau des verres optiques
complémentaire¶
© ISO 2018 – All rights reserved
i
ISO/FDIS 21575:2018(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national
standards bodies (ISO member bodies). The work of preparing International Standards is normally
carried out through ISO technical committees. Each member body interested in a subject for which a
technical committee has been established has the right to be represented on that committee.
International organizations, governmental and non‐governmental, in liaison with ISO, also take part in
the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Deleted: ).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents). Deleted: ).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html. Deleted: .
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics,
Subcommittee SC 3, Optical materials and components.
© ISO 2018 – All rights reserved
ii
ISO 21575:2018(E)
Introduction
There are two commonly used methods for measurement of the chemical resistance of optical glass:
The powder method and the surface method. The powder method has simpler procedures for the
sample preparation since it does not require a homogeneously polished surface.
© ISO 2018 – All rights reserved
iii
FINAL DRAFT INTERNATIONAL STANDARD ISO 21575:2018(E)
Optics and photonics — Optical materials and components —
The powder test method for the water resistance of optical
glass
1 Scope
This document specifies the general procedures of the powder test method for the water resistance of
optical glass.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3310‐1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 4797, Laboratory glassware — Boiling flasks with conical ground joints
ISO 4799, Laboratory glassware — Condensers
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Principles
The glass is ground into particles of diameter within the range of 425 µm to 600 µm. A powder sample Deleted: The powdered
equivalent to the specific gravity in grams is placed in a platinum basket. The basket is placed in a flask
of silica glass and boiled for 60 m
...
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