OSI) International Standard 3511/2 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION+MEXAYHAPOAHAR OPIAHW3AUMA NO CTAHAAPTW3AUWM+ORGANISATION INTERNATIONALE DE NORMALISATION Process measurement control functions and instrumentation - Symbolic representation Part 2: Extension of basic requirements Fonctionset instrumentationpourlamesureet la regulation desprocessus industriels-Representationsymbolique Partie2:Extensiondesprincipesdebase First edition-1984-07-01 UDC744.43:62-52:003.62 Ref.No.ISO3511/2-1984(E) Descriptors : technical drawing, graphic symbols, measuring instrument, control devices, adjusting systems. Price based on 8 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of developing International interested in a subject for which a technical committee has been authorized 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 circulated to the member bodies for approval before their acceptance as International Standards by the ISOCouncil. International StandardISO3511/2wasdeveloped byTechnical CommitteeiSO/TC10, Technical drawings, and was circulated to the member bodies in May 1983. It has been approved by the member bodies of the following countries: Australia India Sweden Austria Italy Switzerland Belgium Japan United Kingdom Brazif Netherlands USA Czechoslovakia Norway USSR Germany, F.R. Poland No member body expressed disapproval of the document. This partofIso3511was developedbysub-committee3,Graphicalsymbols for instru- mentation. The symbols are intended to be used to represent functions and, in special cases, equipment on technical drawings such as schematic diagrams or process flow- diagrams. However, this field of engineering is closely related to electrical instrumenta- tion dealt with by IEC/TC 65 or in part by IEC/SC 3A. For this reason there has been close coordination in a joint working group and the results were accepted by members of ISO and IEC. International Organization for Standardization,1984 . Printed in Switzerland ISO3511/2-1984(E) INTERNATIONALSTANDARD Process measurement control functions and instrumentation Symbolic representation Part 2: Extension of basic requirements Introduction The symbols are used on piping and instrumentation diagrams and engineering line diagrams. This International Standard has been devised to provide a universal means of communication among the various interests involved in the design, manufacture, installation and operation 2 Reference of measurement and control equipment used in the process in- dustries. IEc 117-15, Recommended graphical symbols; graphical sym- bols -Part 15:Binary logic elements. Requirements within the industries vary considerably; in recognition of this, this International Standard is presented in four parts, as follows: 3 Definitions Part 1: Basic requirements (directed towards the needs of The definitions given in ISo 3511/1 equally apply to this part of those employing comparatively simple measurements and ISO3511. controi means). The following definition also applies: Part 2: Extension of basic requirements. Part 3: Detailed symbols for instrument interconnection 3.1 sensing element: That part of an instrument loop that diagrams. first senses the value of a process variable and that assumes a Part 4: Basic symbols for process computer,interface,and predetermined and intelligible state or output. shared display/control functions.1) NOTE -- The sensing element may be separate from or integral with The four parts together are intended to: another functional element of a loop, but should be given an individual tag number only if it is separate. a) meet the requirements of those who, possibly employ- Examples: ing more sophisticated measurement and control means, W