Duty factor (of a machine or apparatus)
The ratio or percentage of the duration of working under load to the duration of the complete cycle of operations specified.
Note: The term " duty cycle " is sometimes used in Great Britain with this meaning, but this usage is deprecated.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM