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 978-0-626-20630-7 SANS 742:2008 Edition 1 and nat. amdt 1 ISO 3:1973 Edition 1SOUTH AFRICAN NATIONAL STANDARD Preferred numbers Series of preferred
4、numbers This national standard is the identical implementation of ISO 3:1973 and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 i
5、nternational code +27 12 www.stansa.co.za Standards South Africa This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 742:2008 Edition 1 and nat. amdt 1 ISO 3:1973 Edition 1 Table of changes Change No. Date Scope Nat. amdt 1 2008 Amended to cha
6、nge the number from SANS 10003 to SANS 742. National foreword This South African standard was approved by National Committee StanSA TC 5140.17, Rubber and rubber products, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This SANS document
7、 was published in March 2008. This SANS document supersedes SANS 10003:2004. This standard may only be used and printed by approved subscription and freemailing clients of the SABS.Lu Y INTERNATIONAL STANDARD INTERNATIONAL ORGANlZATlON FOR STANDARDIZATION l EXAYHAPOAHAR OPTAHW3AUMII l-IO CTAHAAPTW3A
8、IJWW.ORGANISATION INTERNATIONALE DE NORMALISATION Preferred numbers - Series of preferred numbers First edition - 1973-04-01 UDC 389.171 Descriptors : preferred numbers. Ref. No. IS0 3-1973 (E) Price based on 4 pages SANS 742:2008This standard may only be used and printed by approved subscription an
9、d freemailing clients of the SABS.FOREWORD IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body intere
10、sted in a subject for which a Technical Committee has been set up 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. Draft International Standards adopted by the Technical Committees are
11、circulated to the Member Bodies for approval before their acceptance as International Standards by the IS0 Council. Prior to 1972, the results of the work of the Technical Committees were published as IS0 Recommendations; these documents are now in the process of being transformed into International
12、 Standards. As part of this process, International Standard IS0 3 replaces IS0 Recommendation R 3-1954 drawn up by Technical Committee I SO/TC 19, Preferred numbers. The Member Bodies of the following countries approved the Recommendation : Australia India Austria Israel Belgium Italy Chile Mex ice
13、Denmark Netherlands Finland New Zealand France Norway Germany Portuga I Hungary South Africa, Rep. of Spain Sweden Switzerland United Kingdom U.S.A. U.S.S.R. Yugoslavia No Member Body expressed disapproval of the Recommendation. International Organization for Standardization, 1973 l Printed in Switz
14、erland SANS 742:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.INTERNATIONAL STANDARD IS0 34973 (E) Preferred numbers - Series of preferred numbers 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies series of preferred
15、numbers. 1 SANS 742:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.IS0 3-1973 (E) 2 BASIC SERIES OF PREFERRED NUMBERS R5 * Basic series R 10 R 20 R 40 Serial number Theoretical values Mantissae of Calculated logarithms values Percentage di
16、fferences t between basic series and calculated values % (1) (2) (3) (4) (5) (6) (7) (8) 1,w 1 ,oo 1 ,oo 1 ,oo 0 000 1 ,oooo 0 1,w 1 025 1,0593 + 0,07 1,12 1,12 2 050 1,122o - 0,18 I,18 3 0,75 1,1885 - 0,71 1,25 1,25 13 4 100 1,2589 - 0,71 1,32 5 125 1,3335 - 1,Ol I,40 1,40 6 150 1,4125 - 0,88 1,50
17、7 175 1,4962 + 0,25 1,60 1,60 1,60 1,60 8 200 1,5849 + 0,95 I,70 9 225 1,6788 + I,26 1,80 1,80 10 250 17783 + 1,22 1,90 11 275 1,8836 + 0,87 2,m 2, if it is not limited, mention shall be made of at least one of the terms. 4.2 Terminology 4.2.1 theoretical values : The extended term value of Examples
18、 : &i+, (z) N, etc. R 5/2 (I . 1000000) - Series limited by the terms 1 and 1 000 000 and including both these terms. 4.2.2 calculated values (see section 2, column 7) : Values approximating to the theoretical values, expressed to 5 significant figures (the relative error in comparison with the theo
19、retical values is less than l/20 000). R IO/3 (. 80.) - Series unlimited in both directions and including the term 80. R 20/4 (112 . ) - Series limited in the lower direction to 112 inclusive. 4.2.3 preferred numbers : Values rounded off in accordance with columns R 5, R 10, R 20, R 40 and R 80 (see
20、 section 2, columns 1 to 4, and section 3). R 40/5 ( . . . 60) - Series limited in the upper direction to 60 inclusive. 4.2.4 serial numbers : An arithmetic series of consecutive numbers indicating the preferred numbers starting with 0 for the preferred number l,OO. NOTE - The derived series R 10/3
21、(1 . . . ), which is obtained, from 1, by taking every third term of the series R 10, comprises the following terms : 1, 2,4,8, 16, 31,5, . . . . Its ratio is about 2. 3 SANS 742:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.IS0 3-1973 (E
22、) 4.6.2 In general, if and the derived series is designated by r is the index of the basic series r = 5, 10, 20 or 40, Rr/p(.10N40.) p is the pitch of the derived series, i.e. the number of Lastly, if x is any integral number, positive, zero or steps in the basic series required to build up the deri
23、ved series, negative, any term of the derived series is the ratio of the derived series is l(p/40X 10 (Plr) x = I() IOPl On the other hand, if N is a positive integral number, the term of identification of the derived series is 10 N/40 SANS 742:2008 Standards South AfricaThis standard may only be used and printed by approved subscription and freemailing clients of the SABS.
