Electrical Reference
Meter CAT Ratings
Understand measurement categories and why voltage rating alone is not enough.
CAT rating describes transient-energy environment, not measurement quality. Match both category and voltage to the point of measurement.
Selection
- Identify where the measurement sits relative to the service and distribution system.
- Use a meter, leads, and accessories rated for the environment.
Before use
- Inspect meter/leads, verify fuse/input-jack configuration, and prove operation on a known source.
Common mistakes
- Reading only the maximum voltage marking.
- Using unrated adapters or damaged leads.
Verify
- Follow employer procedures and manufacturer limitations for the exact instrument.