www bzfxw com BRITISH STANDARD BS EN 25580 1992 ISO 5580 1985 Specification for Minimum requirements for industrial radiographic illuminators for non destructive testing This European Standard EN 2558[.]
BRITISH STANDARD Specification for Minimum requirements for industrial radiographic illuminators for non-destructive testing This European Standard EN 25580:1992 has the status of a British Standard BS EN 25580:1992 ISO 5580:1985 BS EN 25580:1992 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom This British Standard, having been prepared under the direction of the General Mechanical Engineering Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 June 1992 © BSI 02-1999 The following BSI references relate to the work on this standard: Committee reference GME/23 Draft for approval 90/80071 DC ISBN 580 20471 Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standardiseringsraad Suomen Standardisoimisliito, r.y Association franỗaise de normalisation Deutsches Institut fỹr Normung e.V Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Nederlands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portuguès da Qualidade Asociación Espola de Normalización y Certificación Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 25580:1992 Contents Cooperating organizations National foreword Foreword of EN 25580 Scope and field of application Characteristics of radiographic illuminators Determination of certain characteristics Marking Recommendations for use Figure — Light luminance measurement National appendix NA (informative) © BSI 02-1999 Page Inside front cover ii 3 4 Inside back cover i BS EN 25580:1992 National foreword This British Standard has been prepared under the direction of the General Mechanical Engineering Standards Policy Committee and is the English language version of EN 25580:1992 “Non-destructive testing — Industrial radiographic illuminators — Minimum requirements” published by the European Committee for Standardization (CEN) EN 25580:1992 is identical with ISO 5580:1985 published by the International Organization for Standardization (ISO) National appendix NA gives the constitution of the committees responsible for UK participation in the preparation of this standard 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 Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 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 table on the inside front cover ii © BSI 02-1999 EUROPEAN STANDARD EN 25580 NORME EUROPÉENNE April 1992 EUROPÄISCHE NORM UDC 620.179.152.05:620.186 Descriptors: Non-destructive tests, industrial radiography, radiographic illuminators, equipment specifications, screens: Display, luminance, divergence, lighting, optical measurements, marking English version Non-destructive testing Industrial radiographic illuminators Minimum requirements (ISO 5580:1985) Essais non destructifs — Négatoscopes utilisés en radiographie industrielle — Exigences minimales (ISO 5580:1985) Zerstörungsfreie Prüfung — Betrachtungsgeräte für die industrielle Radiographie — Minimale Anforderungen (ISO 5580:1985) This European Standard was approved by CEN on 1992-03-27 CEN members are bound to comply with the CEN/CENELEC 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 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) 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © CEN 1992 Copyright reserved to all CEN members Ref No EN 25580:1992 E EN 25580:1992 Foreword In 1990, ISO 5580:1985 was submitted to the CEN Primary Questionnaire procedure Following the positive result of this procedure, the CEN Technical Board, agreed to submit ISO 5580:1985, without modifications, to Formal Vote The result of the Formal Vote was positive National standards identical to this European Standard shall be published at the latest by 92-10-31 and conflicting national standards shall be withdrawn at the latest by 92-10-31 In accordance with the CEN/CENELEC Common Rules, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom © BSI 02-1999 EN 25580:1992 Scope and field of application This International Standard specifies the minimum requirements for industrial illuminators used for viewing radiographs The function of the illuminator is to allow the viewing of radiographs The illuminator shall guarantee the same safety of personnel as an electric apparatus with maximum voltage, insulation and earthing which is required by corresponding safety standards of electrotechnics in each country where these are applied Characteristics of radiographic illuminators 2.1 Mechanical construction An illuminator consists of the housing with one of the sides being the viewing screen illuminated from the inside This screen can itself be the diffusing screen This housing may also contain a system for thermal protection of the radiographs; this system may or may not be ventilated For the viewing of wet radiographs, the illuminator shall be so designed as to prevent penetration of the liquid if the radiograph comes into contact with the screen 2.2 Viewing screen The screens shall be easy to clean and shall be made of a material which is resistant to scratching during cleaning processes recommended by the manufacturer and during film viewing NOTE The screen may be a combination of elements, all of which should be resistant to heat in terms of deformation and discoloration The size of the screens shall allow the viewing of a radiograph without excessive glare reaching the eyes of the operator Should the illuminator be used for viewing radiographs of different sizes, a system of covering masks shall be provided 2.3 Luminance The screen luminance required depends on the density of the radiographs The following luminance levels are recommended for the perception of information at various density levels The luminance (or brightness) of the illuminated radiograph shall be not less than: — 30 cd/m2 for film densities < 2,5 — 10 cd/m2 for film densities > 2,5 and, wherever possible, approximately 100 cd/m2 or higher These minimum values require the following screen luminance: Film density 1,5 2,5 3,5 4,5 Minimum screen luminance cd/m2 300 000 000 10 000 10 000 30 000 100 000 300 000 NOTE The illuminator may be provided with a device for continuous control of screen luminance 2.4 Colour of light The colour of the light used to illuminate the radiograph is normally white However, in the case of a film with an emulsion type yielding a monocoloured image, light with adapted colours may be used if they have been recommended by the film manufacturers 2.5 Diffusion of light If the illuminator has a diffusing screen, the light shall be sufficiently divergent so that both eyes of the observer receive rays from all parts of the screen The diffusion factor s9 shall exceed 0,7 (see 3.1) 2.6 Uniformity of illumination The screen shall be uniformly illuminated, the uniformity factor g being higher than 0,5 (see 3.2) 2.7 Disturbing light The housing, blinds and covering masks shall be constructed in such a manner that no disturbing light hinders the viewing of the radiographs (see clause 3) 2.8 Anti-glare device Each illuminator shall be fitted with an anti-glare device which, by manual or automatic operation, prevents the operator from being subjected to excessive glare when the radiograph is removed © BSI 02-1999 EN 25580:1992 2.9 Heating Appropriate precautions shall be taken to ensure that the temperature of the housing does not exceed 60 °C at the usual contact surfaces after h of intermittent operation (50 % switched on with maximum of 15 s duration at an ambient temperature of 20 °C) Further precautions shall be taken to ensure that a radiograph of density does not warp after a continuous viewing time of and h of intermittent operation of the illuminator Determination of certain characteristics All photometric measurements shall be carried out in a dark room The luminance meter has to be used in the middle part of its measuring scale Moreover, light escaping from the illuminator even when the viewing screen is completely masked shall not affect the measurements 3.1 Divergence and dispersion of light (of diffusing screens) The luminance shall be measured on a semi-circle, the centre of which is the centre of the screen and the diameter of which is approximately the same as the maximum dimension of the screen, but at least 50 cm The luminance shall be measured with the aid of an appropriate luminance meter, the sensitive surface of which is a tangent to the curve of the circle (see the Figure) These measurements shall be made at angles of 45° (L45), 20° (L20) and 5° (L5) related to the normal The diffusion factor s9 shall be calculated according to the formula L45 + L 20 s9 = -2 L5 The measurements shall be made successively in both senses of rotation The average of the four highest and the average of the four lowest results shall be found, which give the average arithmetical values of the luminance L max and L The uniformity factor g shall then be calculated according to the formula L g = -L max 3.3 Nominal power consumption The nominal power consumption is the number of watts being consumed by the illuminator after it has been in continuous operation at full luminance for a minimum period of 30 Marking A plate which is attached to the illuminator shall give the following information : a) nominal operating voltage or permissible voltage range; b) nominal main frequency or permissible frequency range; c) whether for use with both direct and alternating current or only with one or the other; d) nominal power consumption; e) maximum luminance in candelas per square metre Recommendations for use Operating instructions shall be provided with each illuminator to indicate: a) the operation of the apparatus; b) instructions for the mounting and replacement of lamps and screens; c) care and maintenance; d) safety precautions; e) frequency of checking luminance levels 3.2 Uniformity of screen luminance The measurements shall be made with the aid of an illumination photometer or other suitable instrument If the screen is rectangular, it shall be divided into squares, each side of the squares measuring 3,5 cm, the luminance of each being measured separately If the screen is circular, the same basic procedure shall be followed In both cases, the network of the squares shall be so arranged that the middle square is centred in the middle of the screen © BSI 02-1999 BS EN 25580:1992 Figure — Light luminance measurement © BSI 02-1999 blank BS EN 25580:1992 National appendix NA (informative) The United Kingdom participation in the preparation of this European Standard was entrusted by the General Mechanical Engineering Standards Policy Committee (GME/-) to Technical Committee GME/23 upon which the following bodies were represented: Aluminium Federation Associated Offices Technical Committee Association of Consulting Engineers BEAMA Ltd BNF Metals Technology Centre British Airways British Chemical Engineering Contractors’ Association British Gas plc British Institute of Non-destructive Testing British Photographic Association British Steel Industry Electricity Industry in United Kingdom Health and Safety Executive Institute of Physics Institute of Quality Assurance Light Metal Founders’ Association Lloyd’s Register of Shipping Ministry of Defence NAMAS Power Generation Contractors’ Association (BEAMA Ltd.) Royal Society of Chemistry Society of British Aerospace Companies Limited Society of Motor Manufacturers and Traders Limited Steel Casting Research and Trade Association The Welding Institute © BSI 02-1999 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI Ð 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 international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: 020 8996 9001 Fax: 020 8996 7001 In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: 020 8996 7111 Fax: 020 8996 7048 Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: 020 8996 7002 Fax: 020 8996 7001 Copyright Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means ± electronic, photocopying, recording or otherwise ± without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager Tel: 020 8996 7070