What is the primary purpose of the "CAT" rating on electrical measurement equipment?

The primary purpose of the "CAT" rating on electrical measurement equipment is to ensure safety during use. The CAT rating, which stands for Category rating, identifies the level of protection the device offers against electrical hazards in various environments. It helps users determine the appropriate tool for specific electrical work, especially when working with high voltages.

For instance, devices rated for CAT II are suitable for use on circuits directly connected to the building's electrical supply, while CAT III devices are meant for equipment in the facility's main electrical distribution, and CAT IV indicates safety for use at the source of the supply. This system of categorization is crucial for ensuring that technicians use equipment appropriate for the environments in which they are working, thus minimizing the risk of electric shock or equipment damage.