Instrument Naming
On a Piping and Instrumentation Diagram, instruments are designated by an alphanumeric code or tag.
Instrument NamingThese 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 | - |
