The Explorer didn’t carry a dedicated electrician. The ship’s engineers and radio officer would have been responsible for electrical maintenance and repairs. A multimeter is an essential tool for diagnosing electrical faults. Nowadays multimeters tend to be small digital devices. In Explorer’s service days, the rather bulky Avometer would have been used.
The Avometer could measure amps (current) volts (electrical potential) and ohms (resistance), hence the eponymous AVO. The original Avo, as it was commonly referred to was introduced in 1923 by Post Office engineer Donald Macadie and remained in production in various models until 2008.
The Avo in the photograph is not the ship’s original equipment but was kindly donated by the late Brian Murdoch who was then a volunteer on board. It is however identical to the ship’s equipment.