1、 STD-BSI BS EN IS0 7944-ENGL 1998 m Lb24669 0716464 46T m BRITISH STANDARD Optics and optical instruments - Reference wavelengths The European Standard EN IS0 7944A998 has the status of a British Standard ICs 17.180.01 BS EN IS0 7944:1998 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPY
2、RIGHT LAW BS EN IS0 7944:1998 been prepared under the direction of the Consumer Amd. No. Date Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect on 16 August 1998 O BSI 1998 ISBN O 680 30030 7 National foreword Text affected This Britis
3、h Standard is the English language version of EN IS0 79441998. It is identical with IS0 7944.1998. It supersedes BS 70171988 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CPWA72, ptics and optical instruments, which has the responsibility to: - aid
4、enquires to undestand the te% - present to the responsible international/European committee any enquiries on the hterpretation, or proposals for change, and keep the UK interests informed; - monitor related intedonal and European developments and promulgate them in the UK. A list of organizations re
5、presented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British
6、 Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British S
7、tandard 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 itself confer immunity from legal obligations. Summary of pages This document comprises a front cov
8、er, an inside front cover, the EN IS0 title page, the EN IS0 foreword page, the IS0 title page, page ii, pages 1 and 2, an inside back cover and a back cover STDmBSI BS EN IS0 7944-ENGL 1998 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM 1624669 0716466 232 EN IS0 7944 June 1998 ICs 17.1 80.01 De
9、scriptors: see IS0 document English version Optics and optical instruments - Reference wavelengths (IS0 7944: 1 998) Optique et instruments doptique - Longueurs donde de rfrence (IS0 79443998) Optik und optische Instrumente - Bezugswelieningen (IS0 7944: 1998) This European Standard was approved by
10、CEN on 15 May 1998. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibiiographical references concerning such national standards
11、may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the C
12、entral Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland. Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kin
13、gdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITC EUROPEEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Central Secretariat: rue de Stassart, 36 8-1050 Brussels O 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN IS0 79W199
14、8 E EN IS0 7944:1998 Foreword The text of the International Standard IS0 7944:1998 has been prepared by Technical Committee ISOITC 172 “Optics and optical instruments“ in collaboration with Technical Committee CENTTC 170 “Ophthalmic optics“, the secretariat of which is held by DIN. This European Sta
15、ndard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 1998, and conflicting national standards shall be withdrawn at the latest by December 1998. According to the CENICENELEC Internal Regulations, the national
16、standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endors
17、ement notice The text of the International Standard IS0 7944:1998 was approved by CEN as a European Standard without any modification. STD.BS1 BS EN IS0 7944-ENGL L998 = Lb24bb9 07Lb4b8 005 EN IS0 7944:1998 INTERNATIONAL STANDARD IS0 7944 Second edition 1998-06-01 Optics and optical instruments - Re
18、ference wavelengths Optique et instruments doptique - Longueurs donde de rfrence Reference number IS0 7944: 1998( E) - STD-BSI BS EN IS0 7944-ENGL 1498 Lb24bb9 07Lb4b9 T4L = EN IS0 7944:1998 For e w o r d IS0 (the International Organization for Standardization) is a worldwide federation of national
19、standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical cornmittees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internationa
20、l organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft international Standards adopted by the technical committees
21、 are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 7944 was prepared by Technical Committee ISOiTC 172, Optics and optical instruments. This second edition cancel
22、s and replaces the first edition (IS0 7944:1984), which has been technically revised. Descriptors: optics, optical equipment, ophthalmic equipment. optical tests, testing conditions, reference data, wavelengths. ii * v, * - STD.BS1 BS EN IS0 7944-ENGL II998 II624669 0736470 763 m EN IS0 7944:1998 Op
23、tics and optical instruments - Reference wavelengths 1 Scope This International Standard specifies two reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, as well as ophthalmic lenses. It defines the associated principal refractive indices
24、 and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions. 2 Reference wavelengths, principal dispersions and Abbe numbers 2.1 General The reference wavelengths are the mercury e-line 546,07 nm (see 2.2) and the helium d-line 587,56
25、nm (see 2.3). For non-ophthalmic applications the mercury e-line shall be the reference wavelength. Other wavelengths which may be used in addition to these reference wavelengths are given in tables 1,2 and 3. NOTE 2.2 Mercury e-line 546,07 nm For the future, it is envisaged that only one reference
26、wavelength is to be specified, even for ophthalmic use. The associated principal refractive index ne is the refractive index at the green mercury e-line and the associated principal dispersion is - n, , where nF1 is the refractive index at the blue cadmium F-line; nc is the refractive index at the r
27、ed cadmium Cl-line. The Abbe number Ve with regard to this reference wavelength and this principal dispersion is defined as: ne - 1 n, - nc ve = 2.3 Helium d-line 587,56 nm The associated principal refractive index nd is the refractive index at the yellow helium d-line and the associated principal d
28、ispersion is % - nc , where 4= is the refractive index at the blue hydrogen F-line; EN IS0 7944:1998 Violet Blue Blue Blue Green mercury mercury cadmium hydrogen mercury h-line g-line F-line F-line e-line Hg Hg Cd H Hg 404,66 a5,83 479,99 m,i3 6,07 - - - 546,07 ne - - - - nC is the refractive index
29、at the red hydrogen C-line. Yellow Red Red Red helium cadmium hydrogen helium d-line C-line C-line r-line He Cd H He 5876 643,a5 m,27 ?06,52 587,56 - - - - - - nu The Abbe number Vd with regard to this reference wavelength and this principal dispersion is defined as: Spectral lines Tab11 Ultraviolet
30、 mercury i-line e Element Rb cs Hg Hg Hg Hg Wavelength nm 780,O 852,111) 1 013,982) 1 128,66 1 395,l 1 529,6 Hg Hg Hg 1 813,l 1 9701 2 3254 I Wavelength nm I 365,011) I Reference I Principal refractive r index 1 - 1) This cingle line of the Hg-triplet should be used. 1 Table 3 - Recommended laser wa
31、velengths Active medium He-Ne He-Ne Nd: YAG Wavelength 1064,l BS EN IS0 7944A998 BSI 389 Chiswick High Road London w4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the in
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