To further understand instrument abbreviations used in instrumentation and process diagrams, we have presented more examples of the common combinations of instrument abbreviations you may likely come across. They include abbreviations for switches and alarm devices, transmitters, solenoids, relays, computing devices, primary elements, test points, well or probe, viewing devices e.g glass, safety devices as well as final elements.
The main objective of bringing many possible combinations of these process instruments is to drive home the understanding of how they are formed such that once you see them being used in a process or instrumentation diagram or even conceptual or flow diagrams, you will immediately be in a position to identify them and know what they are being used for.
First Letters
|
Initiating, Measured, Variable
|
Switches & Alarm Devices*
|
Transmitters
|
Solenoids,
Relays,
Computing
Devices
|
Primary
Element
|
Test Point
|
Well or Probe
|
Viewing
Device,
Glass
|
Safety
Device
|
Final
Element
|
||||
High**
|
Low
|
Comb
|
Recording
|
Indicating
|
Blind
|
|||||||||
| A | Analysis | ASH | ASL | ASHL | ART | AIT | AT | AY | AE | AP | AW | AV | ||
| B | Burner/ Combustion |
BSH | BSL | BSHL | BRT | BIT | BT | BY | BE | BW | BG | BZ | ||
| C | User's Choice | |||||||||||||
| D | User's Choice | |||||||||||||
| E | Voltage | ESH | ESL | ESHL | ERT | EIT | ET | EY | EE | EZ | ||||
| F | Flow Rate | FSH | FSL | FSHL | FRT | FIT | FT | FY | FE | FP | FG | FV | ||
| FQ | Flow Quantity | FQSH | FQSL | FQIT | FQT | FQY | FQE | FQV | ||||||
| FF | Flow Ratio | FFSH | FFSL | FE | ||||||||||
| G | User's Choice | |||||||||||||
| H | Hand | HS | HV | |||||||||||
| I | Current | ISH | ISL | ISHL | IRT | IIT | IT | IY | IE | IZ | ||||
| J | Power | JSH | JSL | JSHL | JRT | JIT | JT | JY | JE | JV | ||||
| K | Time | KSH | KSL | Cell | KSHL | KIT | KT | KY | KE | KV | ||||
| L | Level | LSH | LSL | LSHL | LRT | LIT | LT | LY | LE | LW | LG | LV | ||
| M | User's Choice | |||||||||||||
| N | User's Choice | |||||||||||||
| O | User's Choice | |||||||||||||
| P | Pressure/ Vaccum |
PSH | PSL | PSHL | PRT | PIT | PT | PY | PE | PP | PSV, PSE | PV | ||
| PD | Pressure, Differential |
PDSH | PDSL | PDRT | PDIT | PDT | PDY | PE | PP | PDV | ||||
| Q | Quantity | QSH | QSL | QSHL | QRT | QIT | QT | QE | QZ | |||||
| R | Radiation | RSH | RSL | RSHL | RRT | RIT | RT | RY | RE | RW | RZ | |||
| S | Speed/ Frequency |
SSH | SSL | SSHL | SRT | SIT | ST | SY | SE | SV | ||||
| T | Temperature | TSH | TSL | TSHL | TRT | TIT | TT | TY | TE | TP | TW | TSE | TV | |
| TD | Temperature, Differential |
TDSH | TDSL | TDRT | TDIT | TDT | TDY | TE | TP | TW | TDV | |||
| U | Multivaraible | UY | UV | |||||||||||
| V | Vibration/ Machinery Analysis |
VSH | VSL | VSHL | VRT | VIT | VT | VY | VE | VZ | ||||
| W | Weight/ Force |
WSH | WSL | WSHL | WRT | WIT | WT | WY | WE | WZ | ||||
| WD | Weight/ Force, Differential |
WDSH | WDSL | WDRT | WDIT | WDT | WDY | WE | WDZ | |||||
| X | Unclassified | |||||||||||||
| Y | Event/State/ Presence |
YSH | YSL | YY | YE | YZ | ||||||||
| Z | Position/ Dimension |
ZSH | ZSL | ZSHL | ZRT | ZIT | ZT | ZY | ZE | ZV | ||||
| ZD | Gauging/ Deviation |
ZDSH | ZDSL | ZDRT | ZDIT | ZDT | ZDY | ZDE | ZDV | |||||
*A, Alarm, the annuciating device, may be used in the same way as S, switch, the switching device.
** The letters H and L may be omitted in the undefined case.
The table above is a guide. It does not cover all possible combinations of instrument abbreviations that one may encounter in the process industry.
Note that apart from the combinations above, there are some other possible combinations when it comes to instrument abbreviations. Some combinations which might not be common in your process plant are shown in the table below:
Instrument Abbreviation
|
Meaning or Designation Used to Qualify Instrument
|
FO
|
Restriction Orifice
|
FRK, HIK
|
Control Stations
|
FX
|
Accessories
|
TJR
|
Scanning Recorder
|
LLH
|
Pilot Light
|
PFR
|
Ratio
|
KQI
|
Running Time Indicator
|
QQI
|
Indicating Counter
|
WKIC
|
Rate-of-Weight-Loss Controller
|
HMS
|
Hand Momentary Switch
|
