ISO 8255-2:2013

Microscopes - Cover glasses - Part 2: Quality of materials, standards of finish and mode of packaging

ISO 8255-2:2013 specifies requirements and methods of test for the quality of material, standards of finish, and mode of packaging for microscope cover glasses. ISO 8255-2:2013 is applicable to microscope cover glasses for use in transmitted light microscopy (400 nm to 760 nm).

Microscopes — Lamelles couvre-objet — Partie 2: Qualité des matériaux, normes de finition et mode d'emballage

General Information

• Status: Published
• Publication Date: 08-Sep-2013
• ICS: 37.020 - Optical equipment
• Technical Committee: ISO/TC 172/SC 5 - Microscopes and endoscopes
• Drafting Committee: ISO/TC 172/SC 5 - Microscopes and endoscopes
• Current Stage: 9060 - Close of review
• Completion Date: 02-Dec-2028

Relations

• Consolidated By: ISO 11747:2012/Amd 1:2017 - Rice - Determination of rice kernel resistance to extrusion after cooking - Amendment 1
• Effective Date: 06-Jun-2022
• Revises: ISO 8255-2:1997 - Optics and optical instruments - Microscopes - Cover glasses - Part 2: Quality of materials, standards of finish and mode of packaging
• Effective Date: 27-Oct-2012

Overview

ISO 8255-2:2013 - Microscopes - Cover glasses - Part 2 specifies requirements and test methods for the quality of materials, standards of finish, and mode of packaging for microscope cover glasses used in transmitted light microscopy (400–760 nm). It complements ISO 8255-1 (dimensional tolerances and optical properties) by addressing material quality, surface defects, packaging suitability, sampling and test procedures.

Key topics and requirements

• Scope: Applicable to cover glasses intended for transmitted-light microscopes (400–760 nm).
• Visual inspection conditions: Observations by the unaided eye (vision 1.0) under diffuse “cool white” illumination at ~1 500 ±150 lx; tests valid within six months of packaging.
• Surface quality & inclusions: Freedom from pits, seeds, cords, stones, lines, abrasions, scratches and cracks (AQL 1.5).
• Cleanliness & cloudiness: Free of cloudiness, fingerprints and particulate contamination (AQL 1.5).
• Edge finish: No chipped corners or nicks exceeding 1.0 mm length and 0.5 mm depth (AQL 1.0).
• Non-flatness and non-parallelism:
  • Waviness must pass the specified test method.
  • Thickness variation within a single glass (≤ 60 mm max length) no more than half the total thickness tolerance from ISO 8255-1; in a sample of 100, accept up to five failures.
• Durability (chemical resistance/solubility): Surface chemical durability and resistance to atmospheric attack must meet solubility test criteria.
• Adhesion: Cover glasses must be free from adhesion defects (AQL 1.5).
• Residual stress / birefringence: For polarized light use, optical path difference ≤ 5 nm measured through the principal plane (inspection level S‑2, AQL 1.0).
• Sampling & acceptance: Lot inspection sampling follows ISO 2859-1; Annex A provides sample sizes and single sampling plans.
• Packaging & marking: Packages must allow contamination-free handling, correct labelling and stated counts/mass.

Practical applications and users

• Manufacturers and suppliers of microscope slides and cover glasses use ISO 8255-2 to set production, inspection and packaging criteria.
• Quality managers and procurement professionals use the standard to specify accepted lots and supplier certification.
• Microscopy labs (research, clinical, industrial) rely on compliant cover glasses to ensure optical performance in transmitted-light and polarized-light imaging.
• Test labs and inspectors apply the described test methods and AQL sampling plans for conformity assessment.

Related standards

• ISO 8255-1:2011 - Dimensional tolerances, thickness and optical properties.
• ISO 2859-1:1999 - Sampling procedures for inspection by attributes (AQL schemes).
• ISO 11455:1995 - Determination of birefringence in raw optical glass.

Keywords: ISO 8255-2, microscope cover glasses, cover glass quality, transmitted light microscopy, birefringence, packaging, surface quality, AQL, sampling, test methods.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 8255-2
Second edition
2013-09-15
Microscopes — Cover glasses —
Part 2:
Quality of materials, standards of
finish and mode of packaging
Microscopes — Lamelles couvre-objet —
Partie 2: Qualité des matériaux, normes de finition et mode d’emballage
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 Transparency and colour . 2
4.2 Non-flatness (waviness) and non-parallelism . 2
4.3 Durability . 3
4.4 Surface quality and inclusions . 3
4.5 Edge finish. 3
4.6 Cleanliness and cloudiness . 3
4.7 Adhesion . 3
4.8 Residual stress/birefringence . 3
5 Sampling . 3
5.1 General . 3
5.2 Quality measurement for cover glasses for conformance with this part of ISO 8255 . 3
5.3 Drawing of samples and units inspection . 4
6 Test methods . 4
6.1 General . 4
6.2 Package suitability . 4
6.3 Adhesion . 5
6.4 Cleanliness and cloudiness . 5
6.5 Surface quality and inclusions . 5
6.6 Transparency and colour . 6
6.7 Edge finish. 6
6.8 Non-flatness (waviness) and non-parallelism . 6
6.9 Durability — Chemical durability of surface and resistance to atmospheric
attack (Solubility) . 6
6.10 Residual stress/birefringence . 7
7 Marking/labelling . 7
8 Packaging . 7
Annex A (normative) Sample size code letters and single sampling plans for normal inspection .8
Bibliography .10
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. 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. 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.
The committee responsible for this document is ISO/TC 172, Optics and Photonics, Subcommittee SC 5,
Microscopes and endoscopes.
This second edition cancels and replaces the first edition (ISO 8255-2:1997), of which it constitutes a
minor revision.
ISO 8255 consists of the following parts, under the general title Microscopes — Cover glasses:
— Part 1: Dimensional tolerances, thickness and optical properties
— Part 2: Quality of materials, standards of finish and mode of packaging
iv © ISO 2013 – All rights reserved

Introduction
The data given in this part of ISO 8255 are intended to provide for adequate performance of the product
for the end user. They are applicable to most products in use and have been adapted to take into account
the relevant national standards in force. Dimensions and optical qualities are specified in ISO 8255-1.
INTERNATIONAL STANDARD ISO 8255-2:2013(E)
Microscopes — Cover glasses —
Part 2:
Quality of materials, standards of finish and mode of
packaging
1 Scope
This part of ISO 8255 specifies requirements and methods of test for the quality of material, standards
of finish, and mode of packaging for microscope cover glasses.
This part of ISO 8255 is applicable to microscope cover glasses for use in transmitted light microscopy
(400 nm to 760 nm).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 2859-1:1999, Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by
acceptance quality limit (AQL) for lot-by-lot inspection
ISO 8255-1:2011, Dimensional tolerances, thickness, and optical properties
ISO 11455:1995, Raw optical glass — Determination of birefringence
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
seed
small bubbles in glass, sometimes elongated
3.2
cord
vitreous compositional inhomogeneities in glass (also known as striae, ream, or glassy knots)
3.3
line
fine parallel line on glass surface in direction of draw
3.4
nick
place where minute piece(s) of glass have been removed from edges of glass, giving rise to poor edge finish
3.5
cleanliness
freedom from visible contamination such as fingerprints, particulate matter, or residue left from
cleaning process
3.6
cloudiness
haze
light scattering or reduced transparency due to surface deterioration typically as a result of atmospheric
attack in the presence of humidity and CO
3.7
abrasion
surface damage and pitting typically caused by vibration of one slide surface on another during packaging
or during shipment and handling
3.8
acceptance quality limit
AQL
quality level that is the worst tolerable process average when a continuing series of lots is submitted for
acceptance sampling
Note 1 to entry: This concept only applies when a sampling scheme with rules for switching and discontinuation,
such as in ISO 2859-1 and in ISO 3951, is used.
Note 2 to entry: Although individual lots with quality as bad as the acceptance quality limit may be accepted
with fairly high probability, the designation of an acceptance quality limit does not suggest that this is a desirable
quality level. Sampling schemes found in International Standards such as this part of ISO 2859, with their rules
for switching and for discontinuation of sampling inspection, are designed to encourage suppliers to have process
averages consistently better than the AQL. Otherwise, there is a high risk that the inspection severity will be
switched to tightened inspection under which the criteria for lot acceptance become more demanding. Once
on tightened inspection, unless action is taken to improve the process, it is very likely that the rule requiring
discontinuation of sampling inspection pending such improvement will be invoked.
[SOURCE: ISO 2859-1:1999, definition 3.1.26]
3.9
thickness variation
difference between the largest and smallest of thickness measurements, within a cover glass
3.10
vision 1,0
standard visual acuity
ability to see an object so small that the angle subtended at the eye is only one minute of arc (1/60 of a degree)
Note 1 to entry: At 0,6 m the size of a test object is about 1,75 mm.
Note 2 to entry: Since slight colour variation is permitted, definition of colour vision quality of the observer is
not critical.
4 Requirements
4.1 Transparency and colour
The cover glass shall be transparent and colourless when observed as specified in 6.6.
4.2 Non-flatness (waviness) and non-parallelism
4.2.1 Non-flatness (waviness)
The cover glass shall be sufficiently free of waviness to pass the test as specified in 6.8.1.
2 © ISO 2013 – All rights reserved

4.2.2 Non-
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