W. G. Pye & Co was founded in 1896 by W.G Pye as a business of making scientific instruments for research and education for supply to universities and schools. During the First World War, it produced, among other instruments, a range of gun sights, the first Aldis signalling lamps and the Hartree height finder. During the 1920s, it made and sold radio sets but in 1928 sold the radio business to C.O. Stanley who set up Pye Radio Ltd, which later became Pye Ltd.

The instrument business continued as a separate business from Pye Ltd until it was acquired by Pye Ltd in 1946. W.G. Pye & Co Ltd made a variety of electronic instruments, including gauges, oscillators, amplifiers, power supply units and switches. In addition, it made a range of magnetic and chemical instruments. It also made a range of equipment for physics demonstrations in schools including surface tension torsion balances, thermal conductivity apparatus, tuning forks, stands etc.