Smiths Aircraft Instruments “Waymouth” fuel contents gauge test set, dielectric type. A specialist ground maintenance instrument used to test and calibrate aircraft fuel quantity indicators that used capacitive probes in fuel tanks. The unit simulates tank capacitance and electrical conditions so engineers could check gauge accuracy during servicing. Housed in a metal transport casewith instructions inside the lid. Aviation maintenance equipment, mid-20th century, c.1950s–1960s.
