Table 2.3 Typical instrument identification lettersFirst letters
Succeeding lettersMeasurement Modifier Readout or Output function
Modifierpassive functionA = Analysis AlarmB = Burner, Users choice
Users choice Users choicecombustionC = Conductivity
Control(electrical)D = Density or DifferentialSp. GrE = Voltage
(Emf) Sensor (primaryelement)F = Flow rate Ratio(fraction)G = Users
choice Glass or viewingdeviceH = Hand (manual) HighI = Current
(electrical) IndicateJ = Power ScanK = Time or time Time
rateschedule of change Control stationL = Level Light LowM = Users
choice Momentary Middle orintermediateN = Users choice Users choice
Users choice Users choiceO = Users choice Office (restriction)P =
Pressure or Test or samplevacuum pointQ = Quantity Integrate
ortotalizeR = Radiation Record or printS = Speed or Safety
SwitchfrequencyT = Temperature TransmitU = Multi-variable
Multi-function Multi-function Multi-functionV = Vibration. mech.
Valve.analysis Damper or louvreW = Weight or force WellX =
Unclassified X axis Unclassified Unclassified UnclassifiedY = Event
state Y axis Relay. Compute.or presence ConvertZ = Position or Z
axis Drive. Actuator
