3511/2 nternational Standard (TSO Process measurement control functions and instrumentation - Symbolic representation Part 2: Extension of basic requirements Fonctions et instrumentation pour la mesure et la regulation des processus industriels - Représentation symbolique - Partie 2: Extension des principes de base First edition - 1984-07-01 UDC 744.43 : 62-52 : 003.62 Ref. No. 1SO 3511/2-1984 (E) ISO 3511/2-1984 Descriptors : technica! drawing, graphic symbols, measuring instrument, control devices, adjusting systems. Price based on 8 pages Copyright International Organization for Standardization Not for Resale Foreword ISO (the Internationai 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 ISO Council. international Standard ISO 3511/2 was developed by Technical Committee ISO/TC 10, 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 United Kingdom ueder Brazil Netherlands USA Norway Czechoslovakia USSR Germany, F.R. Poland No member body expressed disapproval of the document. This part of IsO 3511 was developed by sub-committee 3, Graphical symbo/s 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 fieid 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 Copyright International Organization for Standardization Not for Resale itted without license from IHS INTERNATIONAL STANDARD ISO 3511/2-1984 (E) Process measurement control functions and instrumentation - Symbolic representation Part 2: Extension of basic requirements O 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 Reference involved in the design, manufacture, installation and operation 2 of measurement and control equipment used in the process in- IEc 117-15, Recommended graphical symbols; graphical sym- dustries. 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 ISO 3511. control 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 eiement of a ioop, but should be given an individual tag number only if it is separate. a) meet the requirements of those who, possibly employ Ex