Based upon ISA 5.1, for P&ID's use V as the first letter of the tag number for vibration. Subsequent modifier letters may include X and Y for the plane of the probe. The letter E for element could apply for a vibration probe such as VE. The proximeter could be tagged VY for relay.
Then probe in one plane could be VXE in one plane and VXE in the other plane. Thrust could ve VZE.
If the probe senses electromagnetic proximity then consider using the sine wave instrument line symbol between the shaft and the tag bubble.
