Tiêu chuẩn iso 03511 2 1984 scan

International Standard @) 3511/2 0 a 4 4g& INTERNATIONAL ORGAN,ZAT,ON ~ORSTANDARDIZATION~ME~~YHAPO~HAfl OPrAHH3AUMR nOCTAH,lAPTM3A,,W, ORGANISATION INTERNATIONALE DE NORMALISATION Process measurement[.]

International Standard @) 0 a 4 4g& 3511/2

INTERNATIONAL ORGAN,ZAT,ON ~ORSTANDARDIZATION~ME~~YHAPO~HAfl OPrAHH3AUMR nOCTAH,lAPTM3A,,W,-ORGANISATION INTERNATIONALE DE NORMALISATION

First edition - 1964-07-01

G3

i

UDC 744.43 : 62-52 : 003.62 Ref No IS0 3511/2-19&l f E)

7

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Descriptors : technical drawing, graphic symbols, measuring instrument, control devices, adjusting systems

`,,,,,`,```,,`,,`,```,,,````,`-`-`,,`,,`,`,,` -Foreword

the IS0 Council

Sweden Switzerland

USA USSR

tion dealt with by IEC/TC 65 or in part by IECYSC 3A For this reason there has been

of IS0 and IEC

0 International Organization for Standardization, 1984 l

Printed in Switzerland

`,,,,,`,```,,`,,`,```,,,````,`-`-`,,`,,`,`,,` -INTERNATIONAL STANDARD IS0 3!511/2-1984 (E)

0 Introduction

dustries

four parts, as follows:

diagrams

used for its actuation;

1 Scope and field of application

2 Reference

bols - Part 15: Binary logic elements

3 Definitions

IS0 3511

3.1 sensing element: That part of an instrument loop that

NOTE - The sensing element may be separate from or integral with another functional element of a loop, but should be given an individual tag number only if it is separate

Examples :

assembly shall be tagged PT

pressure cell shall be tagged PE and the transmitter shall be tagged PT

4 Letter code

4.1 Identifying letters

4.2 Basis for the letter code

1) At present at the stage of draft

1

IS0 3511/2-1994 (E)

Table - Letter code for identification of instrument functions

NOTE - Entries in normal type are identical with the entries in the table of IS0 3511i 1 Entries in italics indicate the supplementary symbols

ultifunction unit

uvre, actua tlng element, unspecified correcting

W Weight or force

cathode-ray tube)

I I upper case lerters snail De usea for tne measured or rnmatrng variable and succeeding letters for display or output function Upper case letters are preferred for modifiers, but lower case letters may be used if this facilitates understanding

2) A note shall be added to specify the property measured,

3) Where a user has a requirement for measured or initiating variables to which letters have not been allocated and are required for repetitive use on a particular contract, the letters allocated to “User’s Choice” may be used provided that they are identified or defined for a particular measured or initiating variable and reserved for that variable Where a user has a requirement for a measured or initiating variable that may be used either once or to

a limited extent, the letter X may be used provided that it is suitably identified or defined

4) The letter U may be used instead of a series of first letters where a multiplicity of inputs representing dissimilar variables feed into a single unit NOTE - Where it is necessary to denote HIGH or LOW, the qualifying letters H or L may be used in association with the instrument symbol Other let- ters may be used, for example for deviation, for rate of change, but these shall be defined on the drawing rather than in the table

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5 Instrument signal lines 6.1.2 Venturi tube

6.1.4 Variable area meter

A

6.1.5 Turbine meter

6.1.6 Volume meter - general

6 Primary elements, correcting elements,

and actuating elements

NOTE - In cases where it is necessary to use detail symbols in func-

tional diagrams the symbols should be as given In IS0 3511!3, slmpli-

fying if possible Examples are as follows

6.1 Flow primary elements

0

[I

Y FQ

3

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6.2 Level instrument connections 6.2.6 Level control valve - mechanical linkage

tvw

float type

x

6.4 Actuating elements

f

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M

P

7 Local control panels

Q

vices panel

8 Signal modifiers, analogue

- al

s a2

- a3

,a1 +a2+a3

-

5

`,,,,,`,```,,`,,`,```,,,````,`-`-`,,`,,`,`,,` -IS0 3!511/2-1984 (E)

ahen al < a2 then Z = al

Jvhen al > a2 then Z = az

when al > a2 then Z = a2 when al < a2 then Z = al

Z = 1 -a

a

when al < a2 then Z = a2

when al > a2 then Z = al

1 :I

when al 2 a2 then Z = al

when al ( a2 then Z = a2

0,75

-

3

3a

-

IS0 3511/2-19&l (E)

10 Action of binary signals on analogue signals

8.11 Digital-to-analogue or analogue-to-digital signal con-

verter

a (digital)

AID

10.1 When B = 1, then Z = A When B = 0, then there are

8.12 On-off relay 1-O

Z (binary)

-

8.13 Bias relay f , + or -, representing relays respectively

9 Binary logic

IEC 117-15

IS0 3511/2-19&l (El

A When B = 1, then there are

A,, & ,’ ~z=1oo%

100%

LLr 6 F = Z=70%

70%