Portable appliance testing, PAT inspection or PAT testing is the name of a process in the United Kingdom, by which electrical appliances are routinely checked for safety. The formal known as in-service inspection and testing of electrical equipment. Testing involves a visual inspection of the equipment and any flexible cables/leads for condition and safety, and also verification of earthing/grounding continuity, ingof the soundness of insulation between the current carrying companants, and any exposed metal parts that may be touched. The formal limits for pass/fail of these electrical tests vary depending on the category of equipment being tested.
Health and safety regulations require that electrical appliances are safe and maintained to prevent harm to workers. Electrical equipment manufacturers recommend testing at regular intervals to ensure continual safety the interval between tests depending on both the type of appliance and the environment in which it is to be used. The European Low Voltage Directive governs the manufacture or importation of electrical appliances. Compliance to this has to be declared and indicated by the display of the CE mark on the product. The responsibility for this lies with the manufacturer or the importer and is monitored by Trading Standards.