Instrument Naming

Instrument Naming On a Piping and Instrumentation Diagram, instruments are designated by an alphanumeric code or tag. These letters go together to form unique Instrumentation Identification. The typical Instrumentation Matrix is a good starting place for typical instrumentation found in a plant.
Letter	First Letter	Second Letter	Third Letter
A	Analyzer	Alarm	-
B	Burner or Combustor	-	-
C	Available	-	-
D	Available	-	-
E	Voltage	Element	-
F	Flow Rate	-	-
G	Available	Glass	-
H	Hand	-	High
I	Current (Electrical)	Indicator	-
J	Power	-	-
K	Time, Schedule	-	-
L	Level	Light	Low
M	Available	-	Middle
N	Available	-	-
O	Available	Orifice	-
P	Pressure	Connection Point (Test)	-
Q	Quantity	-	-
R	Radiation	Record	-
S	Speed	Switch	-
T	Temperature	Transmitter	-
U	Multivariable	Multi-function	-
V	Vibration	Valve	-
W	Weight	Well	-
X	Unclassified	Unclassified	-
Y	Event	-	-
Z	Position	Actuator, Driver	-