What is the standard abbreviation for a phase meter on electrical diagrams?

In electrical diagrams, the standard abbreviation for a phase meter is "PM." This abbreviation is commonly used by professionals in the electrical field to denote a device that measures the phase angle between two or more voltages or currents, which is crucial for analyzing the performance of three-phase electrical systems. Using the correct abbreviation is important for clarity and understanding in diagrams, as it helps ensure that all readers—engineers, technicians, and others—can easily comprehend the equipment being referenced.

The other choices may resemble legitimate abbreviations, but they do not specifically align with established standards in electrical schematics. For instance, "PH" might suggest a reference to phase in a broader sense, while "PMT" and "MAT" lack relevance in this context, as they are not recognized abbreviations for a phase meter. Thus, "PM" is the authoritative choice that accurately reflects the standard terminology in electrical documentation.