BS 3062-1985.pdf
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1、BRITISH STANDARD CONFIRMED JUNE 1990 BS 3062:1985 Incorporating Amendment No. 1 Specification for Ophthalmic lens materials UDC 617.7-76:681.732.066.03 - - BS 3062:1985 This British Standard, having been prepared under the direction of the Optical Equipment Standards Committee, was published under t
2、he authority of the Board of BSI and comes into effect on 28 February 1985 BSI 08-1999 First published April 1959 First revision November 1970 Second revision February 1985 The following BSI references relate to the work on this standard: Committee reference OES/3 Draft for comment 84/65629 DC ISBN
3、0 580 14491 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Optical Equipment Standards Committee (OES/-) to Technical Committee OES/3 upon which the following bodies were represented: Association of Dispensing Opticians Department of
4、Health and Social Security Federation of Manufacturing Opticians Flat Glass Manufacturers Association Institute of Physics Ministry of Defence Amendments issued since publication Amd. No.Date of issueComments 5467September 1986 Indicated by a sideline in the margin - - BS 3062:1985 i Contents Page C
5、ommittees responsibleInside front cover Foreword ii 1Scope1 2Designation1 3Category of material1 4Refractive index and constringence1 5Other properties of ophthalmic materials1 6Freedom from visible defects2 7Flammability2 8Information to be provided by the supplier2 Appendix A Method for determinat
6、ion of refractive index and constringence3 Appendix B Method for determination of yellowness index and absorptivity of white materials3 Appendix C Method for determination of luminous transmittance of all ophthalmic materials and fatigue of photochromic materials3 Appendix D Method for determination
7、 of solar infra-red transmittance5 Appendix E Method for determination of internal quality7 Appendix F Method for assessment of flammability7 Appendix G Bibliography7 Figure 1 Spectral transmittance of heat-absorbing filter4 Table 1 Refractive property tolerances1 Table 2 Spectral irradiance E2 for
8、the infra-red spectral range6 Publications referred toInside back cover - - BS 3062:1985 Foreword This revision of this British Standard was prepared under the direction of the Optical Equipment Standards Committee and supersedes the second edition published in 1970, which is withdrawn. There are th
9、ree main changes from the previous edition. First, this British Standard takes into account the international proposal to standardize the derivation of constringence. Secondly, the method for conditioning glass specimens before determination of their refractive properties has changed slightly. Third
10、ly, the scope has been expanded to cover a greater variety of ophthalmic materials. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itse
11、lf confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be in
12、dicated in the amendment table on the inside front cover. - - BS 3062:1985 1 1 Scope This British Standard specifies requirements for three categories of white or tinted materials used for the manufacture of ophthalmic spectacle lenses. This standard does not specify requirements for contact lens ma
13、terials. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Designation The material shall be designated according to the following: a) category; b) refractive index and constringence (all materials); c) absorptivity (for white materials) or lumino
14、us transmittance (for tinted non-photochromic materials); d) heat-absorbing properties (for tinted materials); e) luminous transmittance in both the clear and dark states (for photochromic materials). 3 Category of material A material shall be described as being of one of the following three categor
15、ies. 4 Refractive index and constringence The refractive index and constringence of all materials shall not differ from the nominal values declared by the supplier see clause 8 a) by more than the appropriate tolerances given in Table 1. The refractive index and constringence shall be determined by
16、the method described in Appendix A using the conditioning method that is appropriate for the material. 5 Other properties of ophthalmic materials 5.1 White materials 5.1.1 When white ophthalmic materials are tested by the method described in B.1, B.2 and B.3.1, the yellowness index shall be between
17、0 and 1.5. 5.1.2 When white ophthalmic materials are tested by the method described in B.1, B.2 and B.3.2 at wavelengths between 500 nm and 580 nm, the average absorptivity shall not be greater than 1 % per 10 mm. Table 1 Refractive property tolerances 5.2 Tinted materials When tinted ophthalmic mat
18、erials are tested by the method described in C.1, C.2.1 and C.3.1, the luminous transmittance shall be within 5 % of the value declared by the supplier see clause 8 b) 2) for values over 40 %. For declared values under 40 %, the luminous transmittance shall be within 2. NOTEFor example, for declared
19、 values (X) over 40, the luminous transmittance will be within X (X 5/100). For declared values of under 40 %, the luminous transmittance will be within X 2 %. 5.3 Heat-absorbing materials If tinted materials are designated as heat-absorbing see clause 8 c), the solar infra-red transmittance of the
20、material, determined by the method described in Appendix D, shall be not greater than the luminous transmittance, when determined by the method described in C.1, C.2.1 and C.3.1. 5.4 Photochromic materials 5.4.1 When the luminous transmittance of a photochromic material in its clear state is determi
21、ned by the method described in C.1, C.2 and C.3.2, it shall not differ from the value declared by the supplier see clause 8 d) 2) by more than 5.0 % of that value. CategoryDescription 1. Ophthalmic glass Material formed by the fusion of inorganic oxides and of which silica is normally a substantial
22、part. 2. Ophthalmic hard resin Material consisting principally of organic thermosetting plastics. 3. Ophthalmic thermo-plastics Material consisting principally of organic thermoplastics. Refractive index, ndTolerance up to and including 1.59 0.001 from 1.59 up to and including 1.69 + 0.001 0.0015 gr
23、eater than 1.69 0.0015 Constringence, VdTolerance up to and including 45 0.5 greater than 45 1.0 NOTE 1For the definition of nd see A.2 and for the definition of Vd see A.3. NOTE 2A closer tolerance is needed for the refractive index when two pieces of material are united to form a lens component wi
24、thout visible indication of the interface in normal use, for example, flat top fused glass bifocal lenses. In this case a tolerance of 0.0003 is recommended. - - BS 3062:1985 5.4.2 When the luminous transmittances for the clear state and the dark state are determined by the method described in C.1,
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