Detail of GB/T 44276.2-2024

Introduction of GB/T 44276.2-2024

GB/T 44276.2-2024 Microscopes - Cover glasses - Part 2: Quality of materials, standards of finish and mode of packaging 1 Scope This document specifies requirements and methods of test for the quality of material, standards of finish, and mode of packaging for microscope cover glasses. This document 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 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection Note: GB/T 2828.1-2012, Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO 2859-1:1999, IDT) ISO 8255-1:2017 Microscopes - Cover glasses - Part 1: Dimensional tolerances, thickness and optical properties Note 1: There is no technical difference between the referenced content of ISO 8255-1:2017 and the referenced content of ISO 8255-1:2011. Note 2: GB/T 44276.1-2024, Microscopes - Cover glasses - Part 1: Dimensional tolerances, thickness and optical properties (ISO 8255-1:2017, IDT) ISO 11455 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 2 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: This concept only applies when a sampling scheme with rules for switching and discontinuation, such as in ISO 2859-1 and in ISO 3951-1 and in ISO 3951-2, is used. Note 2: 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 2859-1, 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: At 0.6 m the size of a test object is about 1.75 mm. Note 2: 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. 4.2.2 Non-parallelism Thickness variation within a single cover glass with maximum length dimension of 60 mm shall be no more than half the total thickness tolerance in ISO 8255-1, when tested according to 6.8.2. Of the sample of 100 cover glasses, accept a maximum of five that do not meet this requirement. 4.3 Durability Glass shall have a surface of sufficient chemical durability and resistance to atmospheric attack to pass the solubility test specified in 6.9. 4.4 Surface quality and inclusions Glass shall be visibly free of pits, seeds, cords, stones, lines, abrasions, scratches, or cracks when observed as specified in 6.5 (AQL 1.5). 4.5 Edge finish The cover glass shall have no chipped corners or nicked edges exceeding 1 mm in length and 0.5 mm in depth (AQL 1.0) when examined as specified in 6.7. 4.6 Cleanliness and cloudiness Cover glasses shall be clean and free of cloudiness, fingerprints, or particulate matter on its surface when observed as specified in 6.4 (AQL 1.5). 4.7 Adhesion Cover glass shall be free from adhesion when tested as specified in 6.3 (AQL 1.5). 4.8 Residual stress/birefringence Cover glass designated for use with polarized light shall not exhibit an optical path difference greater than 5 nm when measured through principal plane of the cover glass as specified in 6.10 (Inspection level S-2. AQL 1.0).

Contents of GB/T 44276.2-2024