1、BRITISH STANDARD BS EN ISO 7944:1998 Optics and optical instruments Reference wavelengths The European Standard EN ISO 7944:1998 has the status of a British Standard ICS 17.180.01BSEN ISO 7944:1998 This British Standard, having been prepared under the direction of the Consumer Products and Services
2、Sector Board, was published under the authority of the Standards Board and comes into effect on 15 August1998 BSI 04-1999 ISBN 0 580 30030 7 National foreword This British Standard is the English language version of EN ISO7944:1998. It is identical with ISO7944:1998. It supersedes BS7017:1988 which
3、is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CPW/172, Optics and optical instruments, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation,
4、or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that
5、CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standar
6、ds Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for
7、 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 cover, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, page ii, pages 1 and 2 andaback c
8、over. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSENISO7944:1998 BSI 04-1999 i Contents Page National foreword Inside
9、 front cover Foreword 2 Foreword ii Text of ISO 7944 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO7944 June1998 ICS 17.180.01 Descriptors: See ISO document English version Optics and optical instruments Reference wavelengths (ISO7944:1998) Optique et instruments doptique Longueur
10、s donde de rfrence (ISO7944:1998) Optik und optische Instrumente Bezugswellenlngen (ISO7944:1998) This European Standard was approved by CEN on 15 May 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the
11、status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards 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).
12、 A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland
13、, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Bruss
14、els 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO7944:1998 EENISO 7944:1988 BSI 04-1999 2 Foreword The text of the International Standard ISO7944:1998 has been prepared by Technical Committee ISO/TC172 “Optics and optica
15、l instruments” in collaboration with Technical Committee CEN/TC170 “Ophthalmic optics”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December1998, and c
16、onflicting national standards shall be withdrawn at the latest by December1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France,
17、 Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the International Standard ISO7944:1998 was approved by CEN as a European Standard without any modification. Contents Page Foreword 2
18、 1 Scope 1 2 Reference wavelengths, principal dispersions and Abbe numbers 1 Table 1 Reference wavelengths and recommended wavelengths in the visible and ultraviolet spectral ranges 1 Table 2 Recommended wavelengths in the infrared spectral range 1 Table 3 Recommended laser wavelengths 2EN ISO 7944:
19、1988 ii BSI 04-1999 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 s
20、ubject 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
21、(IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees 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 St
22、andard ISO7944 was prepared by Technical Committee ISO/TC172, Optics and optical instruments. This second edition cancels and replaces the first edition (ISO7944:1984), which has been technically revised. Descriptors: Optics, optical equipment, ophthalmic equipment, optical tests, testing conditions
23、, reference data, wavelengths.EN ISO 7944:1998 BSI 04-1999 1 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
24、 indices 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-line546,07nm (see2.2) and the helium d-line 58
25、7,56nm (see2.3). 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 Table 1, Table 2 and Table 3. NOTEFor the future, it is envisaged that only one reference wavelength is t
26、o be specified, even for ophthalmic use. 2.2 Mercury e-line 546,07nm The associated principal refractive index n eis the refractive index at the green mercury e-line and the associated principal dispersion is n F 9 n C 9, where The Abbe number v ewith regard to this reference wavelength and this pri
27、ncipal dispersion is defined as: 2.3 Helium d-line 587,56nm The associated principal refractive index n dis the refractive index at the yellow helium d-line and the associated principal dispersion is n F n C , where The Abbe number v dwith regard to this reference wavelength and this principal dispe
28、rsion is defined as: Table 1 Reference wavelengths and recommended wavelengths in the visible and ultraviolet spectral ranges Table 2 Recommended wavelengths in the infrared spectral range n F 9 is the refractive index at the blue cadmium F9-line; n C 9 is the refractive index at the red cadmium C9-
29、line. n F is the refractive index at the blue hydrogen F-line; n C is the refractive index at the red hydrogen C-line. v e n e 1 n F9 n C9 - = v d n d 1 n F n C - = Spectral lines Ultraviolet mercury Violet mercury Blue mercury Blue cadmium Blue hydrogen Green mercury Yellow helium Red cadmium Red h
30、ydrogen Red helium i-line h-line g-line F9-line F-line e-line d-line C9-line C-line r-line Element Hg Hg Hg Cd H Hg He Cd H He Wavelength nm 365,01 a 404,66 435,83 479,99 486,13 546,07 587,56 643,85 656,27 706,52 Reference wavelength nm 546,07 587,56 Principal refractive index n e n d a This single
31、line of the Hg-triplet should be used. Element Rb Cs Hg Hg Hg Hg Hg Hg Hg Wavelength nm 780,0 852,11 a 1013,98 b 1128,66 1395,1 1529,6 1813,1 1970,1 2325,4 a Caesium s-line b Mercury t-lineEN ISO 7944:1998 2 BSI 04-1999 Table 3 Recommended laser wavelengths Active medium He-Ne He-Ne Nd: YAG Waveleng
32、th nm 543,5 632,8 1064,1blankBS EN ISO 7944:1998 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated
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