1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22541-4 SANS 50444:2009 Edition 1 EN 50444:2008 Edition 1SOUTH AFRICAN NATIONAL STANDARD Basic standard for the evaluation of human exposu
4、re to electromagnetic fields from equipment for arc welding and allied processes This national standard is the identical implementation of EN 50444:2008 and is adopted with the permission of the European Committee for Electrotechnical Standardization (CENELEC). WARNING Can only be used in conjunctio
5、n with EN 50445. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 50444:2009 Edit
6、ion 1 EN 50444:2008 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SABS TC 73, Electromagnetic compatibility, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agr
7、eement. This SANS document was published in March 2009. This standard may only be used and printed by approved subscription and freemailing clients of the SABS. EUROPEAN STANDARD EN 50444 NORME EUROPENNE EUROPISCHE NORM February 2008 CENELEC European Committee for Electrotechnical Standardization Co
8、mit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50444:2008 E ICS 13.280
9、; 25.160.10 English version Basic standard for the evaluation of human exposure to electromagnetic fields from equipment for arc welding and allied processes Norme de base pour lvaluation de lexposition des personnes aux champs lectromagntiques dun quipement pour le soudage larc et les techniques co
10、nnexes Grundnorm zur Ermittlung der Exposition von Personen gegenber elektromagnetischen Feldern von Einrichtungen zum Lichtbogenschweien und artverwandten Prozessen This European Standard was approved by CENELEC on 2008-02-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regula
11、tions 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 CENELEC member. This
12、 European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members
13、 are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
14、 Spain, Sweden, Switzerland and the United Kingdom. SANS 50444:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.EN 50444:2008 2 Foreword This European Standard was prepared by the Technical Committee CENELEC TC 26A, Electric arc welding equi
15、pment. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50444 on 2008-02-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2009-02-01
16、 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2011-02-01 This European Standard is to be read in conjunction with EN 50445. This European Standard has been prepared under mandates M/305 and M/351 given to CENELEC by the European Commission and the Eu
17、ropean Free Trade Association. _ SANS 50444:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS. 3 EN 50444:2008 Contents 1 Scope .6 2 Normative references .6 3 Terms and definitions 6 3.1 General.6 3.2 Specific for arc welding and similar appl
18、ications8 4 Physical quantities, units and constants .9 4.1 Quantities and units9 4.2 Constants9 5 Assessment procedures 9 5.1 Arc welding equipment components to be tested 9 5.2 Assessment conditions.9 5.3 Averaging9 5.4 Pulsed or non-sinusoidal welding current.9 5.4.1 General 9 5.4.2 Summation for
19、 basic restriction assessment.10 5.4.2.1 Summation of current density components without phase information .10 5.4.2.2 Summation of currents density components including phase information10 5.4.2.3 Summation of specific absorption rate (SAR) components .11 5.4.3 Summation for reference level assessm
20、ent 11 5.4.3.1 Summation for stimulation effects without phase information11 5.4.3.2 Effective reference level method12 5.4.3.3 Summation for stimulation effects including phase information.13 5.4.3.4 Summation for thermal effects .13 5.4.4 Equivalent frequency of induced current density waveforms 1
21、3 5.5 Conductivity of living tissue 14 5.6 Frequency range limitations .14 5.7 Application of assessment procedures.15 5.8 Measurements16 5.8.1 Measuring equipment 16 5.8.2 Static field measurements .17 5.8.3 Time domain field measurements .17 5.8.4 Broadband field measurements.17 5.8.5 Frequency se
22、lective field measurements 17 5.8.6 Time domain weighted field measurements18 5.9 Analytical calculations 18 5.9.1 General information .18 5.9.2 Derivation of magnetic field based on welding current18 5.9.3 Derivation of induced current density based on magnetic field.19 SANS 50444:2009This standard
23、 may only be used and printed by approved subscription and freemailing clients of the SABS.EN 50444:2008 4 5.10 Numerical calculations20 5.10.1 General information .20 5.10.2 Derivation of magnetic field .20 5.10.3 Derivation of current density using conductive disc models20 5.10.4 Simulations based
24、 on anatomical body models 21 5.10.4.1 General information21 5.10.4.2 Anatomical body models 21 5.10.4.3 Calculation methods.22 5.10.4.4 Position of the body model in relation to the welding cables .22 6 Uncertainty of assessment22 6.1 Including uncertainty.22 6.1.1 General information .22 6.1.2 Sha
25、red uncertainty budget 22 6.1.3 Using uncertainty in comparison against limit values23 6.2 Evaluation of uncertainties .23 6.2.1 Introduction 23 6.2.2 Individual uncertainties 23 6.2.3 Combined uncertainties.23 6.3 Reasonable overall uncertainties .23 6.4 Examples of typical uncertainties .24 7 Asse
26、ssment report .25 7.1 General principles.25 7.2 Items to be recorded in the assessment report25 Annex A (normative) Assessment parameters26 Annex B (informative) Examples for exposure assessment 30 Annex C (informative) Numerical simulation using anatomical body models .39 Annex D (informative) Geom
27、etry factor and field gradients.43 Annex E (informative) Welding current ripple assessment44 Annex F (informative) Summation using first order filter weighting functions46 Annex G (informative) Example for an uncertainty budget 50 Bibliography51 SANS 50444:2009This standard may only be used and prin
28、ted by approved subscription and freemailing clients of the SABS. 5 EN 50444:2008 Figures Figure 1 Average electrical conductivities for homogeneous body modelling from 10 Hz to 10 MHz .14 Figure A.1 Probe position for measurement on welding cables27 Figure A.2 Topology of welding cable for numerica
29、l simulations 28 Figure B.1 Probe position during measurement31 Figure B.2 Planar current density distribution in the disk32 Figure B.3 Welding current waveform and calculation parameters 33 Figure B.4 Induced current density derived from welding current.33 Figure B.5 Spectral components of welding
30、current pulse34 Figure B.6 Summation of induced current density components with phase information 35 Figure B.7 Flux density waveform and r.m.s. values of the spectral components35 Figure B.8 Flux density waveform and r.m.s. values of the spectral components36 Figure B.9 Summation of flux density co
31、mponents with phase information37 Figure B.10 Flux density waveform and r.m.s. values of the spectral components37 Figure D.1 Planar field distribution for different cable arrangements at I 2 = 200 A .43 Figure E.1 Spectral analysis of triangular function44 Figure F.1 Magnetic flux density reference
32、 levels, filter and tabulated values47 Figure F.2 Weighting function phase angles for B and H, filter and tabulated values 47 Figure F.3 Induced current density basic restrictions, filter and tabulated values 48 Figure F.4 Weighting function phase angles for J, filter and tabulated values49 Figure F
33、.5 Comparison of results for example B.7 (first order filter left, tabulated values right).49 Tables Table 1 Permissible assessment procedures for arc welding equipment.15 Table 2 Permissible assessment procedures for welding cables .16 Table 3 Reasonable expanded assessment uncertainties24 Table A.
34、1 Typical parameters for tests with pulsed welding current.26 Table B.1 Induced current density components and phase angles 34 Table B.2 Flux density components 35 Table B.3 Flux density components and phase angles.36 Table B.4 Flux density components and fractional contributions38 Table C.1 Electri
35、cal conductivity of tissue types .41 Table E.1 J simulation results for relevant spectral components (r.m.s. values)45 Table E.2 B calculation results for relevant spectral components (r.m.s. values).45 Table G.1 Example uncertainty budget for broadband field measurement.50 SANS 50444:2009This stand
36、ard may only be used and printed by approved subscription and freemailing clients of the SABS.EN 50444:2008 6 1 Scope This European Standard applies to equipment for arc welding and allied processes designed for use in industrial or domestic environments, including welding power sources, wire feeder
37、s and ancillary equipment, e.g. torches, liquid cooling systems and arc striking and stabilising devices. NOTE Allied processes are for example electric arc cutting and arc spraying. This standard specifies procedures for assessment of electromagnetic fields produced by arc welding equipment and def
38、ines standardized operating conditions and test set-ups. This standard may be used as a basis to demonstrate compliance to national and international guidelines or requirements with regard to human exposure to EMF from arc welding equipment 1 2. Other standards may apply to products covered by this
39、standard. In particular this standard can not be used to demonstrate electromagnetic compatibility with other equipment; nor does it specify any product safety requirements other than those specifically related to human exposure to electromagnetic fields. 2 Normative references The following referen
40、ced documents are indispensable 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. EN 50392 Generic standard to demonstrate the compliance of electronic
41、and electrical apparatus with the basic restrictions related to human exposure to electromagnetic fields (0 Hz 300 GHz) EN 50445 Product family standard to demonstrate compliance of equipment for resistance welding, arc welding and allied processes with the basic restrictions related to human exposu
42、re to electromagnetic fields (0 Hz 300 GHz) EN 60974-1 Arc welding equipment Part 1: Welding power sources (IEC 60974-1) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 General 3.1.1 basic restrictions restrictions on exposure to electric, ma
43、gnetic and electromagnetic fields that are based directly on established health effects and biological considerations 3.1.2 conductivity () ratio of the conduction current density in a medium to the electric field strength 3.1.3 contact current current flowing into the body by touching a conductive
44、object in an electromagnetic field SANS 50444:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS. 7 EN 50444:2008 3.1.4 effective reference level (B L,eff ) level, provided for practical exposure assessment purposes using a broadband measureme
45、nt, derived from frequency dependent reference levels considering the spectral content of the field 3.1.5 EMF electric, magnetic or electromagnetic field 3.1.6 exposure situation that occurs when a person is subjected to electric, magnetic or electromagnetic fields or to contact current other than t
46、hose originating from physiological processes in the body and other natural phenomena 3.1.7 exposure level value of the quantity evaluated when a person is exposed to electromagnetic fields or contact currents 3.1.8 induced current density (J) electromagnetic field induced current per unit area insi
47、de the body 3.1.9 magnetic flux density (B) magnitude of a field vector that is equal to the magnetic field H multiplied by the permeability of the medium B = H (1) 3.1.10 magnetic field strength (H) magnitude of a field vector in a point that results in a force F ron a charge q moving with velocity
48、 v rF r= q ( v r x H r ) (2) or magnetic flux density divided by permeability of the medium 3.1.11 permeability () property of a material which defines the relationship between magnetic flux density B and magnetic field strength H NOTE It is commonly used as the combination of the permeability of fr
49、ee space 0 and the relative permeability R for specific dielectric materials = R 0(3) where is the permeability of the medium expressed in Henry per metre (H m -1 ). 3.1.12 point of investigation (POI) location in space at which the value of E-field, H-field or power density is evaluated NOTE This location is defined in Cartesian, cylindrical or spherical co-ordinates relative to the reference point on the EUT. SANS 50444:2009This standard
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