ISO 21575:2026

Overview

ISO 21575:2026 establishes the standardized powder test method for determining the water resistance of raw optical glass. Published by the International Organization for Standardization (ISO), this standard outlines the general procedures for sample preparation, testing, classification, and reporting of results. Water resistance is a key parameter affecting the durability and performance of optical glass used across scientific, industrial, and technological applications. By providing a systematic assessment method, ISO 21575:2026 supports quality assurance, material selection, and international trade in optical glass.

Key Topics

• Powder Test Method: Utilizes powdered optical glass to evaluate resistance to water, simplifying sample preparation compared to traditional surface methods.
• Preparation of Specimens: Glass is crushed and sieved to obtain particles of specified size, ensuring consistency in testing.
• Apparatus and Procedures: Specifies use of platinum mesh baskets, laboratory glassware, and water baths for controlled testing.
• Quantitative Assessment: Water resistance is determined by measuring mass loss after exposure, with precise classification according to standardized classes.
• Test Report Requirements: Ensures comprehensive documentation, including reference to this standard, details of the procedure, mass loss calculation, and classification results.

Applications

ISO 21575:2026 is vital for stakeholders involved in the production, procurement, and evaluation of optical glass, ensuring material reliability and suitability for end-use. Typical applications include:

• Optical Component Manufacturers: Quality control during the production of lenses, prisms, and other optical elements, ensuring they meet specified water resistance standards.
• Research and Development: Facilitates material research, development of new optical glasses, and benchmarking against international standards.
• Procurement and Supply Chain: Provides a common reference for specifying glass requirements in purchasing contracts and supplier audits.
• Laboratory Testing: Standardizes testing for academic and industrial laboratories evaluating the durability of optical materials.
• International Trade: Harmonizes technical specifications for optical glass in global markets, facilitating trade and regulatory compliance.

Related Standards

Users of ISO 21575:2026 may also reference several related international standards to fully support testing and evaluation processes, including:

• ISO 3310-1: Test sieves - Technical requirements and testing, which is cited for the particle preparation process.
• ISO 3696: Water for analytical laboratory use - Specifications and test methods, establishing requirements for water quality in tests.
• ISO 4797: Laboratory glassware - Boiling flasks with conical ground joints, referenced for apparatus requirements.
• ISO 4799: Laboratory glassware - Condensers, for compatible equipment specifications.

Practical Value

Implementing ISO 21575:2026 provides a harmonized method for assessing water resistance of optical glass, ensuring repeatability, reliability, and international compatibility. Adherence to this standard:

• Improves product consistency and quality control.
• Reduces disputes in quality assurance by providing clear, measurable criteria.
• Supports innovation by offering a benchmark for research into new glass compositions.
• Enhances confidence for manufacturers, suppliers, and customers by establishing transparent material performance evaluations.

For organizations involved in optics, photonics, and precision engineering, ISO 21575:2026 is an essential reference for ensuring the water resistance and reliability of optical glass in both high-performance and everyday applications.