1、BRITISH STANDARD BS EN ISO 9342-1:2005 Optics and optical instruments Test lenses for calibration of focimeters Part 1: Test lenses for focimeters used for measuring spectacle lenses The European Standard EN ISO 9342-1:2005 has the status of a British Standard ICS 11.040.70 BS EN ISO 9342-1:2005 Thi
2、s British Standard was published under the authority of the Standards Policy and Strategy Committee on 13 July 2005 BSI 13 July 2005 ISBN 0 580 46217 X National foreword This British Standard is the official English language version of EN ISO 9342-1:2005. It is identical with ISO 9342-1:2005. This s
3、tandard, together with BS EN ISO 9342-2, supersedes BS EN ISO 9342:1998, which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee CH/172, Ophthalmic optics, to Subcommittee CH/172/3, Spectacles, which has the responsibility to: A list of organizations represen
4、ted on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by usin
5、g the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity fr
6、om legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.
7、 Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendme
8、nts issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORMEN ISO 9342-1 May 2005 ICS 11.040.70 Supersedes EN ISO 9342:1998 English version Optics and optical instruments - Test lenses for calibration of focimeters - Part 1: Test lenses for focimeters used fo
9、r measuring spectacle lenses (ISO 9342-1:2005) Optique et instruments doptique - Verres talons pour ltalonnage des frontofocomtres - Partie 1: Verres talons pour frontofocomtres pour le mesurage des verres de lunettes (ISO 9342-1:2005) Optik und optische Instrumente - Prfglser zur Kalibrierung von S
10、cheitelbrechwert-Messgerten - Teil 1: Prfglser fr Scheitelbrechwert-Messgerte fr die Messung von Brillenglsern (ISO 9342-1:2005) This European Standard was approved by CEN on 4 April 2005. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for gi
11、ving 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 Standard exists in three official ver
12、sions (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 standards bodies of Austria, Belgium,
13、 Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT
14、EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels Ref. No. EN ISO 9342-1:2005: EForeword This document (EN ISO 9342-1:2005) has been prepared by Technical Committee ISO/TC 172 “Optics and optical instruments“ in collaboration with Technica
15、l Committee CEN/TC 170 “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 November 2005, and conflicting national standards shall be with
16、drawn at the latest by November 2005. This document supersedes EN ISO 9342:1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estoni
17、a, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 9342-1:2005 has been approved by CEN as EN ISO 934
18、2-1:2005 without any modifications. EN ISO 9342-1:2005 Reference number ISO 9342-1:2005(E) INTERNATIONAL STANDARD ISO 9342-1 First edition 2005-05-01 Optics and optical instruments Test lenses for calibration of focimeters Part 1: Test lenses for focimeters used for measuring spectacle lenses Optiqu
19、e et instruments doptique Verres talons pour ltalonnage des frontofocomtres Partie 1: Verres talons pour frontofocomtres pour le mesurage des verres de lunettes EN ISO 9342-1:2005iiiii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards b
20、odies (ISO member bodies). The work of preparing International Standards is normally carried 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 organizati
21、ons, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the
22、 ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. 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 t
23、he member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 9342-1 was prepared by Technical Committee ISO/TC 172, Optics an
24、d photonics, Subcommittee SC 7, Ophthalmic optics and instruments. This first edition cancels and replaces ISO 9342:1996, of which Clause 1 and Clauses A.5 to A.7 have been technically revised. ISO 9342 consists of the following parts, under the general title Optics and optical instruments Test lens
25、es for calibration of focimeters: Part 1: Test lenses for focimeters used for measuring spectacle lenses Part 2: Test lenses for focimeters used for measuring contact lenses EN ISO 9342-1:2005iv 1 Optics and optical instruments Test lenses for calibration of focimeters Part 1: Test lenses for focime
26、ters used for measuring spectacle lenses 1 Scope This part of ISO 9342 specifies requirements for test lenses for the calibration of focimeters that are used for the measurement of spectacle form lenses. NOTE It is accepted that other test lenses can also be used with powers within the given range,
27、manufactured to the same standard of accuracy and form, but different back vertex powers. However, only lenses with integer nominal powers, as described in Annex A, can be used for the calibration of digitally-rounding focimeters. 2 Normative references The following referenced documents are indispe
28、nsable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7944, Optics and optical instruments Reference wavelengths 3 Terms and definitions For the
29、purposes of this document, the following terms and definitions apply. 3.1 spherical test lenses lenses used for the calibration of the dioptric power measurements by focimeters, in which the power of each lens is expressed as its back vertex power in dioptres (D) 3.2 prismatic test lenses lenses use
30、d for the calibration of the prismatic deviation measurements by focimeters, in which the prismatic power of each lens is expressed in centimetres deviation per metre distance (cm/m) NOTE The special name for the unit for expressing prismatic power is the “prism dioptre” for which the symbol “ ” is
31、used. 3.3 cylindrical test lenses lenses with cylindrical faces which are used to calibrate the axis marker and axis indicator with respect to the adjustment orientation of the rail NOTE These lenses are usually specially designed and marked. EN ISO 9342-1:2005 2 3.4 reference wavelength wavelengths
32、 specified in ISO 7944 NOTE For the purposes of this part of ISO 9342, the reference wavelengths are either the green mercury e-line ( e= 546,07 nm) or the yellow helium d-line ( d= 587,56 nm). 4 Design requirements and recommendations for test lenses 4.1 General Test lenses shall be made of homogen
33、eous white crown glass with a refractive index n d= 1,523 0,002, or n e= 1,525 0,002 selected to be free of bubbles and striae in an area of 4 mm radius surrounding the centre of the free aperture. The reference wavelength for which the test lenses are calibrated should be stated. Test lenses should
34、 have a protective mount, which is designed so that, when the lens is correctly placed on the lens support, the focimeter is not obstructed. 4.2 Spherical test lenses For a complete set of spherical test lenses the following set of back vertex powers is recommended: 25 D, 20 D, 15 D, 10 D, 5 D, + 5
35、D, + 10 D, + 15 D, + 20 D, + 25 D Spherical test lenses should have a free aperture of at least 15 mm. In order to minimize the influence of spherical aberration, the curvature of the back surface and the centre thickness shall approximately correspond to those of common spectacle lenses. Table 1 gi
36、ves nominal back surface powers and ranges for centre thickness, which will ensure that the lenses are of this form. Table 1 Design range for the standard test lenses Nominal back vertex power BVP m 1 (D) Nominal back surface power BSP m 1 (D) Power range for BSP m 1 (D) Range for centre thickness a
37、 mm 25 20 15 10 5 +5 +10 +15 +20 +25 25 20 15 12 9 5 3 1 0 0 1 2 to 6 2 to 6 2 to 6 2 to 8 2 to 8 3 to 7 3 to 7 5 to 7 7 to 9 9 to 11 NOTE Surface power is defined by the equation: surface power = (refractive index 1) / radius of curvature in metres aThe centre thicknesses are required to guarantee
38、stability in the negative power range. EN ISO 9342-1:20053 4.3 Prismatic test lenses The optical surfaces of prismatic test lenses shall be planar. The number of prismatic test lenses that should be used to adjust or to check a focimeter depends on the measuring range of the instrument. If a test le
39、ns is used, it shall meet the requirements of this part of ISO 9342. For a complete set, the following set of prismatic deviations is recommended: 2 5 10 15 20 4.4 Cylindrical test lenses The test lens shall be a rectangular positive plano-cylinder of at least 5 D and shall have the dimensions shown
40、 in Figure 1. The cylinder axis shall be parallel to the longer side of the rectangle and shall be marked by a centreline. One of the longer sides shall be marked as the reference side. Dimensions in millimetres Key 1 centreline Figure 1 Cylindrical test lens 5 Tolerances 5.1 Tolerances for spherica
41、l test lenses The permissible tolerances for spherical test lenses are specified in Table 2. NOTE In Annex A an example is given for the proper design of test lenses that meet the requirements of Tables 1 and 2 for free apertures of up to 9 mm diameter. EN ISO 9342-1:2005 4 Table 2 Tolerances for sp
42、herical test lenses Nominal back vertex power m 1(D) Tolerance (maximum deviation) m 1(D) 25 20 15 10 5 +5 +10 +15 +20 +25 0,03 0,02 0,02 0,01 0,01 0,01 0,02 0,02 0,03 0,03 5.2 Tolerances for prismatic test lenses The free aperture of prismatic test lenses shall be at least 15 mm. The tolerances sha
43、ll not exceed the values given in Table 3. Table 3 Tolerances for prismatic test lenses Prismatic deviation cm/m ( ) Tolerance cm/m ( ) 2 5 10 15 20 0,02 0,03 0,05 0,10 0,15 5.3 Tolerances for cylindrical test lenses The angular deviation between the cylinder axis and the longer side of the rectangl
44、e (see Figure 1) shall not exceed 20 of arc. The displacement of the centreline from the afocal meridian shall not exceed 0,1 mm. These tolerances shall not be additive and allow the angular deviation between the cylinder axis and the centreline to be greater than 20 of arc. EN ISO 9342-1:20055 Anne
45、x A (informative) Manufacture of test lenses for focimeters A.1 General Spherical test lenses, which meet the tolerances given in 5.1, can be manufactured by observing the following specifications and procedure. To manufacture test lenses according to this annex, the manufacturer will need a selecti
46、on of master test surfaces against which the test lens surfaces can be checked using standard precision optical techniques. A.2 Selection of glass To manufacture spherical test lenses using this method, precision grade homogeneous optical glass shall be used. The refractive index should be known to
47、an accuracy of at least 5 10 5 . Glass should be selected with a refractive index n e= 1,525 0,001; n d= 1,523 0,001. The dispersion value should be = 59 4. Schott glass K5 1)is an example of a suitable glass. A.3 Calculation of nominal back surface radius of curvature The nominal radius of the back
48、 surface (i.e. the surface that is put onto the lens support of the focimeter) is found by using Table 1. For every nominal back vertex power a nominal back surface power is given. The nominal radius of the back surface is found by using the formula given in the Note to Table 1. A.4 Selection of the closest standard radius Using the result of A.3, select from the available master test surfaces the one whose radius is closest to the value calculated according to A.3. A.5 Calculation of lens thickness and selection of front surface radius Using the selected value
