The company was founded in 1921 under the name British Sangamo as the UK subsidiary of the Sangamo Electric Co. of Springfield, Illinois, USA and manufactured, initially, kilowatt hour meters, later expanded its activities to include industrial time switches. In 1936 Sangamo acquired the British Weston Electrical Instrument Co. of Surbiton, Surrey. This company was the United Kingdom subsidiary of the Weston Electrical Instrument Corporation, of Newark, New Jersey, USA, a company founded by Dr. Weston (a pioneer in the field of electrical measurements), and recognised as one of the worlds leading manufacturers of electrical measuring and associated equipment.