In-service inspection and testing of electrical equipment, commonly known as, Portable Appliance Testing (PAT) is the process of inspecting and testing electrical appliances to ensure they are safe to use. It involves both a visual inspection and, where necessary, electrical testing using specialist equipment.
PAT testing applies to any portable electrical appliance—meaning any device that can be moved and plugged into a power supply. This includes items such as kettles, computers, extension leads, printers, and power tools. Over time, these appliances can become damaged or develop faults, increasing the risk of electric shock, burns, or fire.