Isa s5.5

STANDARD

ISA–5.5–1985
Formerly ISA–S5.5–1985

Graphic Symbols for Process Displays

NOTICE OF COPYRIGHT
This is a copyrighted document and may not be copied or distributed in any form or manner without the permission of ISA. This copy of the document was made for the sole use of the person to whom ISA provided it and is subject to the restrictions stated in ISA’s license to that person.It may not be provided to any other person in print, electronic, or any other form. Violations of ISA’s copyright will be prosecuted to the fullest extent of the law and may result in substantial civil and criminal penalties.

Approved 3 February 1986
TM

ISA–The Instrumentation, Systems, and Automation Society

ISA-5.5-1985, Graphic Symbols for Process Displays ISBN 0-87664-935-5Copyright © 1985 by the Instrument Society of America. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), without the prior written permission of the publisher. ISA 67 Alexander Drive P.O. Box 12277 ResearchTriangle Park, North Carolina 27709

Preface

This preface is included for informational purposes and is not a part of ISA-5.5-1985. This Standard has been prepared as a part of the service of ISA toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static, but should be subject to periodic review. Toward this end, the Society welcomesall comments and criticisms and asks that they be addressed to the Secretary, Standards and Practices Board, ISA, 67 Alexander Drive, P.O. Box 12277, Research Triangle Park, North Carolina 27709, Telephone (919) 549-8411, e-mail: standards@isa.org. The ISA Standards and Practices Department is aware of the growing need for attention to the metric system of units in general and the InternationalSystem of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to U.S.A. users of ISA Standards of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all newand revised standards to the greatest extent possible. The Metric Practice Guide, which has been published by the Institute of Electrical and Electronics Engineers as ANSI/IEEE Std. 268-1982, and future revisions will be the reference guide for definitions, symbols, abbreviations, and conversion factors. It is the policy of ISA to encourage and welcome the participation of all concerned individualsand interests in the development of ISA Standards. Participation in the ISA Standards-making process by an individual in no way constitutes endorsement by the employer of that individual of ISA or any of the standards which ISA develops. The information contained in this preface, in the footnotes, and in the appendices is included for information only and is not part of the standard. The originaldraft of this document resulted from the committee work of the International Purdue Workshop on Industrial Computer Systems, the Man/ Machine Communication Committee TC-6. The use of graphic symbols representing entities and characteristics of processes has evolved rapidly during the course of the last decade. Technology has allowed the presentation of a physical process to be represented andcontrolled by the use of computers and advanced electronic systems. These systems use video-display technologies such as CRTs, plasma screens, and other media to present to the user a graphic representation of his process. It is through these devices and the symbology used to represent the process in question that the user monitors and controls the particular operation. Process displays convey...