Tracked Changes. Automatic electrical controls. Particular requirements for automatic electrical air flow, water flow and water level sensing controls|Probes, Water, Liquid controllers, Controllers, Level control, Liquid-level measurement, Air-conditioning systems, Electrical safety, Control devices, Boilers, Automatic control systems, Cut-out devices, Flow regulators, Electric regulators, Water supply (buildings), Air, Control equipment, Electric control equipment, Space-heating systems, Air control devices, Household equipment, Safety devices, Flow control, Electrical household appliances, Flow measurement