Australian/New Zealand Standard

Transcription

1 AS/NZS 1020:1995 Australian/New Zealand Standard The control of undesirable static electricity

2 AS/NZS 1020:1995 This Joint Australian/New Zealand Standard was prepared by Joint Technical Committee EL/25, Control of Undesirable Static Charges. It was approved on behalf of the Council of Standards Australia on 20 December 1994 and on behalf of the Council of Standards New Zealand on 12 December It was published on 5 March The following interests are represented on Committee EL/25: Australia Post Australian Chamber of Commerce and Industry Australian Electrical and Electronic Manufacturers Association Australian Institute of Petroleum Chemical Confederation of Australia Department of Mineral Resources, N.S.W. Department of Minerals and Energy, W.A. Insurance Council of Australia Plastics Industry Association Plastics and Rubber Institute Telecom Australia WorkCover Authority of N.S.W. Review of Standards. To keep abreast of progress in industry, Joint Australian/New Zealand Standards are subject to periodic review and are kept up to date by the issue of amendments or new editions as necessary. It is important therefore that Standards users ensure that they are in possession of the latest edition, and any amendments thereto. Full details of all Joint Standards and related publications will be found in the Standards Australia and Standards New Zealand Catalogue of Publications; this information is supplemented each month by the magazines The Australian Standard and Standards New Zealand, which subscribing members receive, and which give details of new publications, new editions and amendments, and of withdrawn Standards. Suggestions for improvements to Joint Standards, addressed to the head office of either Standards Australia or Standards New Zealand, are welcomed. Notification of any inaccuracy or ambiguity found in a Joint Australian/New Zealand Standard should be made without delay in order that the matter may be investigated and appropriate action taken.

3 AS/NZS 1020:1995 Australian/New Zealand Standard The control of undesirable static electricity First published in Australia as AS Second edition First published in New Zealand as NZS/AS 1020:1984. Jointly revised and designated as Joint Standard AS/NZS 1020:1995. PUBLISHED JOINTLY BY: STANDARDS AUSTRALIA 1 The Crescent, Homebush NSW 2140 Australia STANDARDS NEW ZEALAND Level 10, Standards House, 155 The Terrace, Wellington 6001 New Zealand ISBN

4 AS / NZS 1020: PREFACE This Joint Standard was prepared by the Standards Australia/Standards New Zealand Committee EL/25 on the Control of Undesirable Static Charges following a review of AS The major change to this Standard is that the referenced documents have been updated. There are no technical changes. The Standard has also been published as a joint Standard to reflect the common requirements applying in both countries. The term informative has been used in this Standard to define the application of the appendix to which it applies. An informative appendix is only for information and guidance. Copyright STANDARDS AUSTRALIA/ STANDARDS NEW ZEALAND Users of Standards are reminded that copyright subsists in all Standards Australia and Standards New Zealand publications and software. Except where the Copyright Act allows and except where provided for below no publications or software produced by Standards Australia or Standards New Zealand may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from Standards Australia or Standards New Zealand. Permission may be conditional on an appropriate royalty payment. Australian requests for permission and information on commercial software royalties should be directed to the head office of Standards Australia. New Zealand requests should be directed to Standards New Zealand. Up to 10 percent of the technical content pages of a Standard may be copied for use exclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia or Standards New Zealand. Inclusion of copyright material in computer software programs is also permitted without royalty payment provided such programs are used exclusively in-house by the creators of the programs. Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standard is amended or revised. The number and date of the Standard should therefore be clearly identified. The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts is subject to the payment of a royalty. This policy may be varied by Standards Australia or Standards New Zealand at any time.

5 3 AS /NZS 1020:1995 CONTENTS Page SECTION 1 SCOPE AND GENERAL 1.1 SCOPE PURPOSE REFERENCEDDOCUMENTS DEFINITIONS... 9 SECTION 2 GENERATION, INDUCTION AND DANGERS BASIC CONSIDERATIONS 2.1 GENERATIONOFSTATIC INDUCTIONOFSTATIC COMMONSOURCESOFGENERATION FIREANDEXPLOSIONDANGERS REMOVAL OF FIRE AND EXPLOSION DANGERS WORKING SURFACES AND FLOOR SURFACE COVERINGS SECTION 3 STATIC DISCHARGES 3.1 NATUREOFSTATICDISCHARGES ENERGYOFASTATICDISCHARGE SECTION 4 SOLID OBJECTS 4.1 SELECTION OF AN APPROPRIATE CONTROL METHOD CONDUCTINGOBJECTS NON-CONDUCTINGOBJECTS SECTION 5 PERSONS 5.1 GENERAL WEARING APPAREL (OTHER THAN FOOTWEAR) EARTHINGOFPERSONSBYFOOTWEAR OTHERMEANSOFEARTHINGPERSONS SECTION 6 LIQUIDS 6.1 INTRODUCTION SELECTION AND APPLICATION OF AN APPROPRIATE CONTROLMETHOD DISSIPATING CHARGE FROM INSTALLATIONS DISSIPATINGCHARGEFROMLIQUIDS CONDUCTIVITY IMPROVERS (ANTISTATIC ADDITIVES) REDUCING THE LIKELIHOOD OF STATIC DISCHARGES ABOVE ALIQUIDSURFACE AVOIDANCEOFTURBULENCE AVOIDANCEOFCONTAMINANTS AVOIDANCEOFHIGHFLOWVELOCITIES USEOFRELAXATIONSECTIONS STATICCHARGEREDUCERS METALLICPIPING... 29

6 AS / NZS 1020: Page 6.13 HOSESANDCOUPLINGS FILLINGOFVESSELS NON-CONDUCTINGVESSELS TRANSFER OF SMALL QUANTITIES (less than 25 L) BLENDINGANDMIXING SAMPLINGFROMHIGHPRESSURESOURCES PNEUMATICTRANSFEROFLIQUIDS SPRAYING SWITCHLOADING SECTION 7 GASES 7.1 INTRODUCTION MINIMIZINGSTATICGENERATION PREVENTIONOFSTATICACCUMULATION REMOVAL OF IGNITABLE MATERIALS AND MIXTURES SECTION 8 DUSTS 8.1 INTRODUCTION MINIMIZINGSTATICGENERATION DISSIPATINGCHARGEFROMEQUIPMENT SECTION 9 POWDERED OR GRANULAR SOLIDS 9.1 INTRODUCTION HANDLING CONTROLOFSTATIC SECTION 10 DRIVE AND CONVEYOR BELTS 10.1 GENERATIONOFSTATIC CONTROLOFSTATIC SECTION 11 EXPLOSIVES 11.1 INTRODUCTION ASSESSINGTHEHAZARD MINIMIZINGTHEHAZARD SECTION 12 PRINTING PROCESSES 12.1 INTRODUCTION MINIMIZINGSTATICGENERATION PREVENTIONOFSTATICACCUMULATION REMOVALOFIGNITABLEMIXTURES SECTION 13 COATING, SPREADING AND IMPREGNATING 13.1 INTRODUCTION CONTROL OF STATIC AND REMOVAL OF IGNITABLE MIXTURES.. 44

7 5 AS /NZS 1020:1995 Page SECTION 14 PROCESSING AND CONVERSION OF PLASTICS AND RUBBER MATERIALS 14.1 INTRODUCTION GENERATIONOFSTATIC CONTROLOFSTATIC SOLUTIONCASTINGOFFILM END-USEAPPLICATIONS SECTION 15 DRYCLEANING 15.1 INTRODUCTION CONTROLOFSTATIC SECTION 16 SUNDRY PROCESSES INVOLVING FLAMMABLE AND COMBUSTIBLE LIQUIDS 16.1 LOADINGANDUNLOADINGROADTANKERS RAILTANKWAGONS FUELLINGANDDEFUELLINGAIRCRAFT LOADING AND UNLOADING TANKERS AND BARGES FUELLINGMOTORVEHICLES TRANSFER OF ETHER AND CARBON DISULPHIDE SECTION 17 SUNDRY PROCESSES INVOLVING PRESSURIZED GAS 17.1 DISCHARGEOFCARBONDIOXIDE MIXTURES OF HYDROGEN OR ACETYLENE WITH AIR TRANSFER OF LIQUEFIED PETROLEUM GAS (LPG) STEAMJETS SPRAYPAINTING SECTION 18 HANDLING OF ELECTROSTATIC SENSITIVE DEVICES 18.1 INTRODUCTION BASICPROTECTIONPRINCIPLES LABELLING TYPESOFPACKAGESAVAILABLE SECTION 19 DETECTION OF ELECTRIC POTENTIAL OR ELECTRIC FIELD STRENGTH 19.1 GENERAL NEONLAMPS ELECTROSCOPES OTHERMETHODS SECTION 20 MEASUREMENT OF ELECTRIC POTENTIAL OR ELECTRIC FIELD STRENGTH 20.1 MEASUREMENT OF ELECTRIC POTENTIAL WITH CONTACTINGINSTRUMENTS... 54

8 AS / NZS 1020: Page 20.2 MEASUREMENT OF ELECTRIC POTENTIAL AND ELECTRIC FIELD STRENGTH WITH NON-CONTACTING INSTRUMENTS CALIBRATION OF NON-CONTACTING ELECTRONIC INSTRUMENTS MEASUREMENTSINHAZARDOUSAREAS SECTION 21 DETERMINATION OF CAPACITANCE 21.1 CALCULATIONOFCAPACITANCE CAPACITANCEMEASUREMENT SECTION 22 MEASUREMENT OF CHARGES 22.1 MEASUREMENTOFSTATICCHARGE SECTION 23 MEASUREMENT OF RESISTANCE OR CONDUCTANCE 23.1 GENERAL RESISTANCEOFEARTHINGCIRCUITS RESISTANCE OF MATERIALS AND PRODUCTS PERSONNELRESISTANCETESTER LIQUIDCONDUCTIVITY APPENDICES A EXAMPLES OF SOLVING PRACTICAL PROBLEMS RESULTING FROMSTATIC B FLAMMABLEANDCOMBUSTIBLELIQUIDS C METHOD FOR LAYING AND EARTHING CONDUCTING FLOORING.. 78 D APPROXIMATE MINIMUM IGNITION ENERGIES E CONDUCTING COATINGS FOR DRIVE AND CONVEYOR BELTS... 80

9 7 AS /NZS 1020:1995 STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND Australian/New Zealand Standard The control of undesirable static electricity SECTION 1 SCOPE AND GENERAL 1.1 SCOPE This Standard sets out recommendations for controlling static electricity (hereinafter referred to as static ) which may be generated incidentally by processes or activities and which may present hazards, damage or inconvenience. Considerations relating to the generation of static and the problems it presents in a given environment are given, together with a description of methods and equipment for measuring electric potential, charge, capacitance and resistance parameters associated with electrostatically charged objects. Specific control methods are given for some industries. The provisions of the standard should not be regarded as overriding statutory requirements, but may be construed as working recommendations to be used in conjunction with such requirements. Methods for minimizing the risk of static causing a fire or explosion arising from the use of flammable medical agents are not included, as they are given in AS Similarly, methods for affording protection from lightning are not included, as these are given in AS/NZS 1768, nor does this standard include the earthing systems of patient treatment areas in hospitals and the like. NOTE: Examples of the solving of some practical problems resulting from static are given in Appendix A. 1.2 PURPOSE Static often causes the inadvertent ignition of flammable mixtures. In other instances it can result in inconvenience or operating problems in industrial and commercial processes. The purpose of this standard is therefore to assist in reducing the fire, explosion, damage and nuisance value associated with static, by promoting a better understanding of the principles relating to its generation, outlining conditions under which its presence causes these problems, and recommending methods for its safe dissipation or mitigation. 1.3 REFERENCED DOCUMENTS Standards The following documents are referred to in this Standard: AS 1000 The International System of Units (SI) and its application 1169 Minimizing of combustion hazards arising from the medical use of flammable anaesthetic agents 1332 Conveyor belting Textile reinforced 1596 LP gas Storage and handling 1841 Portable fire extinguishers Part 1: General requirements Part 7: Vapourizing-liquid type 1852 International Electrotechnical Vocabulary 1940 The storage and handling of flammable and combustible liquids COPYRIGHT

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