Portable appliance testing
Portable appliance testing (commonly known as "PAT", "PAT Inspection" or (redundantly) as "PAT Testing") is the name of a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of earthing (grounding) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested.