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1、BRITISH STANDARD BS EN ISO 8598:1998 Incorporating Amendment No. 1 to BS ISO 8598:1996 (renumbers the BS as BS EN ISO 8598:1998) Optics and optical instruments Focimeters ICS 11.040.70 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN IS
2、O 8598:1998 This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 December 1996 BSI 05-1999 The following BSI references relate to the work on this standard: Com
3、mittee reference CH/78/6 Draft for comment 86/55522 DC ISBN 0 580 26872 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee CH/78, Ophthalmic optics, to Subcommmittee CH/78/6, Ophthalmic instruments, upon which the followin
4、g bodies were represented: Association of British Dispensing Opticians Association of British Health-care Industries Association of Contact Lens Manufacturers British College of Optometrists British Contact Lens Association British Medical Association British Spectacle Frame Makers Association Consu
5、mer Policy Committee of BSI Department of Health Department of Trade and Industry (National Physical Laboratory) Federation of Manufacturing Opticians Federation of Ophthalmic and Dispensing Opticians Flat Glass Manufacturers Association OPTIC (UK) Royal College of Ophthalmologists Amendments issued
6、 since publication Amd. No.DateComments 10216October 1998 Implements European Standard Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 8598:1998 BSI 05-1999i Contents Page Committees responsibleInside front cover National forewordi
7、i Foreword2 Forewordiii Text of ISO 85981 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 8598:1998 ii BSI 05-1999 National foreword This British Standard is the English language version of EN IS
8、O 8598:1998 published by the European Committee for Standardization (CEN). This British Standard is published under the direction of the Health and Environment Sector Board whose Technical Committee CH/78 has the responsibility to: aid enquirers to understand the text; present to the responsible int
9、ernational committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTE 1International and European Standards, as well as overseas standards, are available from Customer
10、 Services, BSI, 389 Chiswick High Road, London W4 4AL. It has been assumed in the drafting of this British Standard that the execution of its provisions is entrusted to appropriately qualified and experienced people. ISO 9337, to which reference is made in clause 1, is being prepared in two Parts. P
11、art 1 will describe the procedure for determining the back vertex power of contact lenses using a focimeter conforming to this standard. NOTE 2When adopting the text of the international standard, the textual error given below was discovered. In 3.1, “spectacles frames” should read “spectacle frames
12、”. 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 itself confer immunity from legal obligations. Cross-references Publication referred
13、toCorresponding British Standard ISO 8429:1986BS 6903:1987 Specification for graduated dial scales for ophthalmic instruments (Identical) ISO 9342:1996BS ISO 9342:1996 Optics and optical instruments Test lenses for calibration of focimeters (Identical) Summary of pages This document comprises a fron
14、t cover, an inside front cover, pages i and ii, the EN title page, page 2, the ISO title page, pages ii to iv, pages 1 to 6, 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 indicated in the amendment ta
15、ble on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8598 July 1998 ICS 11.040.70 Descriptors: See ISO document English version Optics and optical instruments
16、 Focimeters (ISO 8598:1996) Optique et instruments doptique Frontofocomtres (ISO 8598:1996) Optik und optische Instrumente Scheitelbrechwert-Megerte (ISO 8598:1996) This European Standard was approved by CEN on 22 June 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations w
17、hich stipulate the conditions for giving this European Standard the 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 S
18、tandard 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 Central Secretariat has the same status as the official versions. CEN members are the national s
19、tandards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, 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 Kom
20、itee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8598:1998 E Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrol
21、led Copy, (c) BSI EN ISO 8598:1998 BSI 05-1999 2 Foreword The text of the International Standard from Technical Committee ISO/TC 172, Optics and optical instruments, of the International Organization for Standardization (ISO) has been taken over as a European Standard by Technical Committee CEN/TC 1
22、70, 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 January 1999, and conflicting national standards shall be withdrawn at the latest by
23、 January 1999. According to CEN/CENELEC Internal Regulations, 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, Switzer
24、land and the United Kingdom. Endorsement notice The text of the International Standard ISO 8598:1996 has been approved by CEN as a European Standard without any modification. NOTENormative references to International Standards are listed in Annex ZA (normative). A-deviations are given in Annex ZB (i
25、nformative). Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 8598:1998 ii BSI 05-1999 Contents Page Forewordiii 1Scope1 2Normat
26、ive references1 3Definitions1 4Design requirements and recommendations for general purpose focimeters2 5Accuracy requirements3 6Testing4 Annex ZA (normative) Normative reference to international publications with their corresponding European publications6 Annex ZB (informative) A-deviations6 Figure
27、1 Permissible movement of the adjusting rail2 Figure 2 Example of a lens support for spectacle lenses2 Table 1 Tolerances of measured vertex power for continuously indicating instruments3 Table 2 Tolerances of measured prismatic power for continuously indicating instruments3 Table 3 Permissible devi
28、ations of measured vertex power reading from the nominal value of the test lenses for digitally rounding instruments3 Table 4 Permissible deviations of measured prismatic power reading from nominal value of the test lenses for digitally rounding instruments4 Licensed Copy: sheffieldun sheffieldun, n
29、a, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 8598:1998 BSI 05-1999iii 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 ca
30、rried 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
31、. ISO collaborates closely with the International Electrotechnical Commission (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
32、approval by at least 75 % of the member bodies casting a vote. International Standard ISO 8598 was prepared by Technical Committee ISO/TC 172, Optics and optical instruments, Subcommittee SC 7, Ophthalmic, endoscopic, metrological instruments and test methods. Licensed Copy: sheffieldun sheffieldun,
33、 na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 8598:1998 BSI 05-19991 1 Scope This International Standard specifies requirements for continuously indicating
34、 focimeters and digitally rounding focimeters with which the vertex powers and prismatic powers of spherical and astigmatic lenses, including lenses mounted in frames and contact lenses, can be measured and with which lenses can be orientated and marked. NOTE 1For the measurement of vertex powers of
35、 contact lenses, see ISO 9337:1), Optics and optical instruments Contact lenses Determination of back vertex power. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publicatio
36、n, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers o
37、f currently valid International Standards. ISO 7944:, Optics and optical instruments Reference wavelengths2). ISO 8429:1986, Optics and optical instruments Ophthalmology Graduated dial scale. ISO 9342:, Optics and optical instruments Test lenses for the calibration of focimeters1). 3 Definitions For
38、 the purposes of this International Standard, the following definitions apply. 3.1 focimeter instrument that is used to measure vertex powers and prismatic effects of spectacle and contact lenses, to orientate and mark uncut lenses, and to verify the correct mounting of lenses in spectacles frames 3
39、.2 continuously indicating focimeter focimeter with a continuous scale 3.3 digitally rounding focimeter focimeter which displays measured values rounded to the nearest incremental value 3.4 lens support aperture on the instrument against which the lens or the contact lens is placed for measurement N
40、OTE 2The focimeter measures the vertex power relative to the surface placed against the lens support. 3.5 adjusting rail movable rail or bar used as the reference axis for spectacles during measurement, which is aligned perpendicularly to the optical axis of the focimeter and parallel to the axis di
41、rection 0 to 180 NOTE 3Also called the lens table or frame rest. 3.6 principal meridians the two meridians of an astigmatic power lens (see 3.10) containing the optical axis; one of the meridians has maximum refractive power, the other meridian has minimum refractive power NOTE 4In general, the two
42、principal meridians are mutually perpendicular to each other (regular astigmatism). 3.7 vertex power there are two vertex powers of a lens 3.7.1 back vertex power reciprocal of the paraxial value of the back vertex focal length measured in metres 3.7.2 front vertex power reciprocal of the paraxial v
43、alue of the front vertex focal length measured in metres NOTE 5Conventionally the back vertex power is specified as the “power” of a spectacle lens, although the front vertex power is required for certain purposes, for example in the measurement of some multifocal lenses. NOTE 6The unit for expressi
44、ng vertex power is the reciprocal metre (m 1). The name for this unit is the “dioptre” for which the symbol is “D”. 3.8 prismatic power deviation of a ray of light through a specified point on a lens NOTE 7The unit for expressing prismatic power is the centimetre per metre (cm/m). The name for this
45、unit is the “prism dioptre” for which the symbol is “%”. 3.9 spherical power lens lens bringing a paraxial pencil of parallel rays to a single point focus NOTE 8This definition could also apply to single-vision aspheric lenses. 1) To be published 2) To be published. (Revision of ISO 7944:1984) Licen
46、sed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:01:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 8598:1998 2 BSI 05-1999 3.10 astigmatic power lens lens bringing a paraxial pencil of parallel rays to two separate line foci mutually at right angles and hence, unlike a spherical lens, havi
47、ng two principal powers NOTE 9One of these powers may be zero, with the corresponding focal line at infinity. Lenses referred to as toric lenses, sphero-cylindrical lenses, and cylinder lenses are all astigmatic lenses. 3.11 centration error of the instrument residual prismatic error of the instrume
48、nt with no lens in place 4 Design requirements and recommendations for general purpose focimeters 4.1 The measuring range shall include vertex powers with a range from at least 20 D to + 20 D and prismatic powers from 0 to at least 5 %. The instrument shall be capable of measuring the axis direction
49、 (see ISO 8429) of cylindrical lenses between 0 and 180. For prisms it shall be possible to determine the direction of the base setting between 0 and 360 4.2 For continuously indicating focimeters, the dioptre scale shall have a scale interval not greater than 0,25 D and shall be readable to the accuracy given in Table 1 and Table 2. For axis directions (see ISO 8429), the scale interval shall not exceed 5 and shall permit interpolations to be made to the nearest degree. For prismatic power readings the interva