Accelerometer, G-Meter, AN-5745, Hucknall Aerodrome, Rolls-Royce Flight Test
This instrument seems to have had a very interesting history. This Accelerometer, made by Bendix part number 3413-2D-A, has a service tag from the WWII-era Rolls Royce Flight Test establishment situated at Hucknall Aerodrome, home of RAF Hucknall north of Nottingham England. The Rolls Royce Flight Test unit tested new engine designs and modifications at Hucknall, including piston and jet powered engines. We might assume that this accelerometer was used in test aircraft by Rolls Royce engineers stationed at Hucknall.
This type of accelerometer also appeared in versions of the Boeing B-17, Consolidated B-24, and North American B-25 bombers of the US Army Air Force during WWII, according to the Maintenance Interchangeability Chart dated Feb 1945.
The accelerometer has 3 pointers: a main pointer that instantaneously rotates counterclockwise when the aircraft experiences negative G's, and clockwise in the instance of positive G's. The two auxiliary pointers located behind the main pointer rotate to indicate the maximum negative or positive G's experienced by the aircraft until reset by turning the knob clockwise.