6426/1 (ISO nternational Standard INTERNATIONALORGANIZATIONFOR STANDARDIZATION+MEKAYHAPOAHAROPTAHM3AUMAOCTAHAAPTW3AWW-ORGANISATION INTERNATIONALEDENORMALISATION Horological vocabulary Part 1 : Technical and scientific definitions Vocabulaire horloger - Partie 1 : Definitions technico-scientifiques First edition - 1982-02-01 UDC 681.11 : 001.4 Ref.No. 1SO 6426/1-1982 (E) ISO 6426/1-1982 Descriptors : clock making, time measuring instruments, vocabulary, definitions, formulas (mathematics). Price based on 7 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of developing Inter- national Standards is carried out through Iso technical committees. Every member body interested 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 so, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. Intrnational. Standard S0 6426/1was developed by Technical Committee ISO/TC 114, Horology, and was circulated to the member bodies in May 1980. It has been approved by the member bodies of the following countries : Australia Japan Romania Czechoslovakia Egypt, Arab Rep. of Spain Switzerland France USSR India The member bodies of the following countries expressed disapproval of the document on technical grounds : Germany, F.R. United Kingdom International Organization for Standardization, 1982 Printed in Switzerland ISO 6426/1-1982 (E) INTERNATIONALSTANDARD Horological vocabulary Part 1 Technical and scientific definitions 1 Scope and field of application in the dates, taken in this order, of the end of the interval (hj) and the beginning of it (h;). This part of Iso 6426 defines the principal technical and scien- tific terms used in the horological industry. These definitions NOTE - In a uniform time scale, by applying formula (1), the expres- apply to time-measuring instruments or to related devices. sion of the duration is given by the relation : ... (3) A table summarizing the values and units of measurement t =a(tj- t) associated with the definitions is given at the end of this part of or even more simply, if a = 1, that is if the uniform time scale ISO6426. servesas a reference: NOTE -- The definitions of technical and commercial terms will form . . (4) the subject of a future International Standard. -= In this case, there is a pure and simple identity between h and t 2 Reference when the indices agree and the unit of duration is the second as defined in the international system (Sl). If, in addition, the in- Iso 31/1, Values and units of space and time. dices are themselves chosen from a completely ordered whole and if j > i, then tj > t; and t > 0. The date (h;) is prior to (hj). 3 Definitions state (E) of an instrument at the instant t; : The dif. 4 The order in which the terms are given is a logical order, ference at a precise marked instant ti, between the date h; without any intention of classification and the numbering of the which it indicates and the reference date H; definitions does not indicate any scale of importance. E; = h; - H; . . . (5) 1 time : Undefined medium in which existing objects appear to develop irreversibly in the changes which they undergo, and The unit of the state is the second. cession. NOTE - If there is direct access to a reference scale of time main- tained by a standard clock for the purpose of marking a date H, the To this medium corresponds a quantity t allowing, over a time checking of a time-keeping instrument maintaining its own scale of scale, the chronological order of events. time h by comparison with the standard consists of dating,that is by simultaneously marking the sameevent intwo scales of time.