TEI Radio Frequency Wattmeter (ex Government), used at Hurstwood Park Hospital in EEG work, circa 1948.

This radio frequency wattmeter was used in neurological work carried out at Hurstwood Park Hospital during the 1940s. The hospital opened in 1938 in the grounds of St Francis Hospital (formerly asylum) and was originally an admissions hospital for inmates. Hurstwood Park became a pioneering centre for neurosurgery during the Second World War. It was staffed by medical personnel evacuated from the National Hospital in London.

Wartime developments in technologies such as radar resulted in rapid advances post-war in the electronics industry. Devices such as this ex-government equipment, made by TEI Limited, were recycled into other industries. A radio frequency wattmeter measures the power of a generator working at radio frequency. It was used in electroencephalogram (EEG) work to measure tiny electrical signals in the brain, to help diagnose epilepsy.