Instrument Abbreviations Used in Instrumentation Diagrams (P&IDs) II ~ Learning Instrumentation And Control Engineering Learning Instrumentation And Control Engineering

Instrument Abbreviations Used in Instrumentation Diagrams (P&IDs) II

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We have already seen how the letters A – Z are combined in instrumentation diagrams to give process instruments unique function and identification in Instrument Abbreviations Used in Instrumentation Diagrams (P&IDs). Since the subject of process instrumentation diagrams is versatile and at the heart of understanding key industrial processes, we present further examples of instrument abbreviations as defined in the ISA 5.1 standard for symbols used in P&IDs. In the table presented below, we have:
(a) A column for the first letter denoting the process variable
(b) A second column denoting the initiating or measured variable
(c) A third column for controllers of various degrees – recording, indicating, blind (denotes a controller without a modifying function such as recording or indicating) and self-actuated control valves designed to regulate diverse process variables
(d) A fourth column for readout devices which can either be recording or indicating as the case maybe.

The table for instrument abbreviations shows many possible combinations for any kind of instrument measuring the defined variables as denoted by the first letter in the first column.

First Letter
Initiating or Measured Variable
Controllers
Read out Devices
Recording
Indicating
Blind
Self-Acutated Control Valves
Recording
Indicating
A Analysis ARC AIC AC
AR AI
B Burner/Combustion BRC BIC BC
BR BI
C User's Choice





D User's Choice





E Voltage ERC EIC EC
ER EI
F Flow Rate FRC FIC FC FCV, FICV FR FI
FQ Flow Quantity FQRC FQIC

FQR FQI
FF Flow Ratio FFRC FFIC FFC
FFR FFI
G User's Choice





H Hand
HIC HC


I CurrentIRC IIC

IR II
J Power JRC JIC

JR JI
K Time KRC KIC KC KCV KR KI
L Level LRC LIC LC LCV LR LI
M User's Choice





N User's Choice





O User's Choice





P Pressure/Vacuum PRC PIC PC PCV PR PI
PD Pressure, Differential PDRC PDIC PDC PDCV PDR PDI
Q Quantity QRC QIC

QR QI
R Radiation RRC RIC RC
RR RI
S Speed/Frequency SRC SIC SC SCV SR SI
T Temperature TRC TIC TC TCV TR TI
TD Temperature, Differential TDRC TDIC TDC TDCV TDR TDI
U Multivariable





V Vibration/Machinery Analysis





W Weight/Force WRC WIC WC WCV WR WI
WD Weight/Force, Differential WDRC WDIC WDC WDCV WDR WDI
X Unclassified Cell Cell Cell Cell Cell Cell
Y Event/State/Presence
YIC YC
YR YI
Z Position/Dimension ZRC ZIC ZC ZCV ZR ZI
ZD Gauging/Deviation ZDRC ZDIC ZDC ZDCV ZDR ZDI