In 1920 Paul's business amalgamated with the Cambridge Scientific Instrument Co. taking the name of Cambridge and Paul. The name was again changed in 1924 to Cambridge Instrument Co. Ltd. In 1937 the original production area was enlarged and again, in 1951, more space was acquired at Friern Park, Finchley, North London for further expansion. The year 1968 saw the Cambridge Instrumentation Co. joining forces with the George Kent Group of Luton, forming the largest independent British manufacturer of industrial instruments. After reorganization, the industrial division was separated from those involved in scientific and medical products and at the same time the Foster Instrument Co. of Letchworth, Herts. was amalgamated with Cambridge Instruments to create Foster Cambridge Ltd.
The George Kent Group combined with BBC Brown Boveri & Co. Ltd., the international electrical engineering organization in late 1974. By December 1975, all personnel had transferred from London to St. Neots, at the same time production of all Fielden Electronics products was moved to the St. Neots site. In 1976 Metrawatt, a Brown Boveri company, was also moved to the St. Neots factory. Kent Industrial Measurements Limited and Kent Process Control were formed from the creation of Brown Boveri Kent Ltd in July 1979. A 1988 merger between BBC and the Swedish organization ASEA resulted in the formation of ABB (ASEA Brown Boveri), bringing Kent into the ABB fold.